1. An association of serum vitamin D concentrations 40 nmol/L with acute respiratory tract infection in young Finnish men
Abstract
“Background:
The effects of vitamin D in regulating bone mineralization are well documented. The action of vitamin D as a key link between Toll-like receptor activation and antibacterial responses in innate immunity has recently been shown. The data suggest that differences in the ability of human populations to produce vitamin D may contribute to susceptibility to microbial infection.
Objective:
We aimed to explore whether an association exists between vitamin D insufficiency and acute respiratory tract infection in young Finnish men.
Design:
Young Finnish men (n 800) serving on a military base in Finland were enrolled for this study. Their serum 25-hydroxyvitamin [25(OH)D] concentrations were measured in July 2002. They were followed for 6 mo, and the number of days of absence from duty due to respiratory infection were counted.
Results:
The mean ( SD) serum 25(OH)D concentrations were 80.2 29.3 nmol/L (n 756). Subjects with serum 25(OH)D concentrations 40 nmol/L (n 24) had significantly (P 0.004) more days of absence from duty due to respiratory infection (median: 4; quartile 1– quartile 3: 2– 6) than did control subjects (2; 0 – 4; n 628; incidence rate ratio 1.63; 95% CI: 1.15, 2.24). We found a significant (P 0.004) association between serum 25(OH)D concentrations and the amount of physical exercise before induction into military service. We also found significantly (P 0.001) lower serum 25(OH)D concentrations in subjects who smoked (72.8 26.6 nmol/L; n 192) than in control subjects (82.9 29.7 nmol/L; n 537).
Conclusion:
Clinical trials of vitamin D supplementation are needed to investigate whether it enhances immunity to microbial infections. Am J Clin Nutr 2007;86:714 –7. KEY”
Links
https://www.ncbi.nlm.nih.gov/pubmed/17823437
Citation
Laaksi, Ilkka, Juhaâ Petri Ruohola, Ville Mattila, Anssi Auvinen, Timo Ylikomi, and Harri Pihlajamki. "Vitamin D Supplementation for the Prevention of Acute Respiratory Tract Infection: A Randomized, Double Blinded Trial among Young Finnish Men." The Journal of Infectious Diseases 202.5 (2010): 809-14.
“Background:
The effects of vitamin D in regulating bone mineralization are well documented. The action of vitamin D as a key link between Toll-like receptor activation and antibacterial responses in innate immunity has recently been shown. The data suggest that differences in the ability of human populations to produce vitamin D may contribute to susceptibility to microbial infection.
Objective:
We aimed to explore whether an association exists between vitamin D insufficiency and acute respiratory tract infection in young Finnish men.
Design:
Young Finnish men (n 800) serving on a military base in Finland were enrolled for this study. Their serum 25-hydroxyvitamin [25(OH)D] concentrations were measured in July 2002. They were followed for 6 mo, and the number of days of absence from duty due to respiratory infection were counted.
Results:
The mean ( SD) serum 25(OH)D concentrations were 80.2 29.3 nmol/L (n 756). Subjects with serum 25(OH)D concentrations 40 nmol/L (n 24) had significantly (P 0.004) more days of absence from duty due to respiratory infection (median: 4; quartile 1– quartile 3: 2– 6) than did control subjects (2; 0 – 4; n 628; incidence rate ratio 1.63; 95% CI: 1.15, 2.24). We found a significant (P 0.004) association between serum 25(OH)D concentrations and the amount of physical exercise before induction into military service. We also found significantly (P 0.001) lower serum 25(OH)D concentrations in subjects who smoked (72.8 26.6 nmol/L; n 192) than in control subjects (82.9 29.7 nmol/L; n 537).
Conclusion:
Clinical trials of vitamin D supplementation are needed to investigate whether it enhances immunity to microbial infections. Am J Clin Nutr 2007;86:714 –7. KEY”
Links
https://www.ncbi.nlm.nih.gov/pubmed/17823437
Citation
Laaksi, Ilkka, Juhaâ Petri Ruohola, Ville Mattila, Anssi Auvinen, Timo Ylikomi, and Harri Pihlajamki. "Vitamin D Supplementation for the Prevention of Acute Respiratory Tract Infection: A Randomized, Double Blinded Trial among Young Finnish Men." The Journal of Infectious Diseases 202.5 (2010): 809-14.
2. Association Between Serum 25-Hydroxyvitamin D Level and Upper Respiratory Tract Infection in the Third National Health and Nutrition Examination Survey
Abstract
“BACKGROUND:
Recent studies suggest a role for vitamin D in innate immunity, including the prevention of respiratory tract infections (RTIs). We hypothesize that serum 25-hydroxyvitamin D (25[OH]D) levels are inversely associated with self-reported recent upper RTI (URTI).
METHODS:
We performed a secondary analysis of the Third National Health and Nutrition Examination Survey, a probability survey of the US population conducted between 1988 and 1994. We examined the association between 25(OH)D level and recent URTI in 18 883 participants 12 years and older. The analysis adjusted for demographics and clinical factors (season, body mass index, smoking history, asthma, and chronic obstructive pulmonary disease).
RESULTS:
The median serum 25(OH)D level was 29 ng/mL (to convert to nanomoles per liter, multiply by 2.496) (interquartile range, 21-37 ng/mL), and 19% (95% confidence interval [CI], 18%-20%) of participants reported a recent URTI. Recent URTI was reported by 24% of participants with 25(OH)D levels less than 10 ng/mL, by 20% with levels of 10 to less than 30 ng/mL, and by 17% with levels of 30 ng/mL or more (P < .001). Even after adjusting for demographic and clinical characteristics, lower 25(OH)D levels were independently associated with recent URTI (compared with 25[OH]D levels of > or =30 ng/mL: odds ratio [OR], 1.36; 95% CI, 1.01-1.84 for <10 ng/mL and 1.24; 1.07-1.43 for 10 to <30 ng/mL). The association between 25(OH)D level and URTI seemed to be stronger in individuals with asthma and chronic obstructive pulmonary disease (OR, 5.67 and 2.26, respectively).
CONCLUSIONS:
Serum 25(OH)D levels are inversely associated with recent URTI. This association may be stronger in those with respiratory tract diseases. Randomized controlled trials are warranted to explore the effects of vitamin D supplementation on RTI.”
Links
https://www.ncbi.nlm.nih.gov/pubmed/19237723
Citation
Ginde, Adit A., Jonathan M. Mansbach, and Carlos A. Camargo. "Association Between Serum 25-Hydroxyvitamin D Level and Upper Respiratory Tract Infection in the Third National Health and Nutrition Examination Survey." Archives of Internal Medicine 169.4 (2009): 384.
“BACKGROUND:
Recent studies suggest a role for vitamin D in innate immunity, including the prevention of respiratory tract infections (RTIs). We hypothesize that serum 25-hydroxyvitamin D (25[OH]D) levels are inversely associated with self-reported recent upper RTI (URTI).
METHODS:
We performed a secondary analysis of the Third National Health and Nutrition Examination Survey, a probability survey of the US population conducted between 1988 and 1994. We examined the association between 25(OH)D level and recent URTI in 18 883 participants 12 years and older. The analysis adjusted for demographics and clinical factors (season, body mass index, smoking history, asthma, and chronic obstructive pulmonary disease).
RESULTS:
The median serum 25(OH)D level was 29 ng/mL (to convert to nanomoles per liter, multiply by 2.496) (interquartile range, 21-37 ng/mL), and 19% (95% confidence interval [CI], 18%-20%) of participants reported a recent URTI. Recent URTI was reported by 24% of participants with 25(OH)D levels less than 10 ng/mL, by 20% with levels of 10 to less than 30 ng/mL, and by 17% with levels of 30 ng/mL or more (P < .001). Even after adjusting for demographic and clinical characteristics, lower 25(OH)D levels were independently associated with recent URTI (compared with 25[OH]D levels of > or =30 ng/mL: odds ratio [OR], 1.36; 95% CI, 1.01-1.84 for <10 ng/mL and 1.24; 1.07-1.43 for 10 to <30 ng/mL). The association between 25(OH)D level and URTI seemed to be stronger in individuals with asthma and chronic obstructive pulmonary disease (OR, 5.67 and 2.26, respectively).
CONCLUSIONS:
Serum 25(OH)D levels are inversely associated with recent URTI. This association may be stronger in those with respiratory tract diseases. Randomized controlled trials are warranted to explore the effects of vitamin D supplementation on RTI.”
Links
https://www.ncbi.nlm.nih.gov/pubmed/19237723
Citation
Ginde, Adit A., Jonathan M. Mansbach, and Carlos A. Camargo. "Association Between Serum 25-Hydroxyvitamin D Level and Upper Respiratory Tract Infection in the Third National Health and Nutrition Examination Survey." Archives of Internal Medicine 169.4 (2009): 384.
3. Association of subclinical vitamin D deficiency in newborns with acute lower respiratory infection and their mothers
Abstract
“Background/Objectives:
There are other benefits of vitamin D than those for bone health. To determine the association of serum 25-hydroxy vitamin D (25(OH)D) concentrations in newborns with acute lower respiratory infection (ALRI) and without clinical signs of rickets, and their mothers. The design comprises a hospital-based case-control study.
Subjects/Methods:
The study group consisted of 25 newborns with ALRI who were admitted to neonatal intensive care unit and their mothers. Controls were 15 healthy newborns of the same age as the study group and their mothers. A commercial radioimmunoassay was used to measure 25(OH)D concentrations in serum for assessing vitamin D status.
Results:
The two groups were similar in gestational week, birth weight, birth height, head circumference, age and gender. The mean serum 25(OH)D concentrations in the study group newborns were lower than those of the control group (9.12±8.88 ng/ml and 16.33±13.42 ng/ml, respectively) (P ¼ 0.011). Also, mean serum 25(OH)D concentrations in the mothers of the study group were lower than those in the mothers of the control group (13.38±16.81 ng/ml and 22.79±16.93 ng/ml respectively) (P ¼ 0.012). In 87.5% of all newborns and 67.5% of all mothers, serum 25(OH)D concentrations were lower than 20 ng/ml. The 25(OH)D concentrations of newborns were highly correlated with mothers’ serum 25(OH)D concentrations.
Conclusions:
Our findings suggest that newborns with subclinical vitamin D deficiency may have an increased risk of suffering from ALRI. The strong positive correlation between newborns’ and mothers’ 25(OH)D concentrations shows that adequate vitamin D supplementation of mothers should be emphasized during pregnancy especially in winter months”
Links
https://www.ncbi.nlm.nih.gov/pubmed/18030309
Citation
Karatekin, G., A. Kaya, Saliholu, H. Balci, and A. Nuholu. "Association of Subclinical Vitamin D Deficiency in Newborns with Acute Lower Respiratory Infection and Their Mothers." European Journal of Clinical Nutrition 63.4 (2007): 473-77.
“Background/Objectives:
There are other benefits of vitamin D than those for bone health. To determine the association of serum 25-hydroxy vitamin D (25(OH)D) concentrations in newborns with acute lower respiratory infection (ALRI) and without clinical signs of rickets, and their mothers. The design comprises a hospital-based case-control study.
Subjects/Methods:
The study group consisted of 25 newborns with ALRI who were admitted to neonatal intensive care unit and their mothers. Controls were 15 healthy newborns of the same age as the study group and their mothers. A commercial radioimmunoassay was used to measure 25(OH)D concentrations in serum for assessing vitamin D status.
Results:
The two groups were similar in gestational week, birth weight, birth height, head circumference, age and gender. The mean serum 25(OH)D concentrations in the study group newborns were lower than those of the control group (9.12±8.88 ng/ml and 16.33±13.42 ng/ml, respectively) (P ¼ 0.011). Also, mean serum 25(OH)D concentrations in the mothers of the study group were lower than those in the mothers of the control group (13.38±16.81 ng/ml and 22.79±16.93 ng/ml respectively) (P ¼ 0.012). In 87.5% of all newborns and 67.5% of all mothers, serum 25(OH)D concentrations were lower than 20 ng/ml. The 25(OH)D concentrations of newborns were highly correlated with mothers’ serum 25(OH)D concentrations.
Conclusions:
Our findings suggest that newborns with subclinical vitamin D deficiency may have an increased risk of suffering from ALRI. The strong positive correlation between newborns’ and mothers’ 25(OH)D concentrations shows that adequate vitamin D supplementation of mothers should be emphasized during pregnancy especially in winter months”
Links
https://www.ncbi.nlm.nih.gov/pubmed/18030309
Citation
Karatekin, G., A. Kaya, Saliholu, H. Balci, and A. Nuholu. "Association of Subclinical Vitamin D Deficiency in Newborns with Acute Lower Respiratory Infection and Their Mothers." European Journal of Clinical Nutrition 63.4 (2007): 473-77.
4. Association of subclinical vitamin D deficiency with severe acute lower respiratory infection in Indian children under 5 years
Abstract
“Objectives:
To determine whether subclinical vitamin D deficiency in Indian children under 5 y of age is a risk factor for severe acute lower respiratory infection (ALRI). Design: A hospital-based case-control study. Setting: Sanjeevani Paediatrics Hospital, a private hospital in Indapur, India.
Participants:
A total of 150 children including 80 cases and 70 controls, aged 2–60 months, were enrolled. Case definition of severe ALRI as given by the World Health Organization was used for cases. Controls were healthy children attending outpatients’ service for immunization. Main outcome measure: Association of serum 25-hydroxyvitamin D3 (25OHD3) with severe ALRI, controlling for demographic and other potential risk factors.
Results:
Serum 25OHD3 increased with age. Factors significantly associated with decreased risk of severe ALRI in univariate analysis were: exclusive breastfeeding in the first 4 months (cases 35/78 (45%), controls 41/64 (64%); P ¼ 0.02); introduction of other dietary liquids than milk only after 6 months (cases 46/70 (66%), controls 31/66 (47%); P ¼ 0.03); use of liquid petroleum cooking fuel (cases 32/80 (40%), controls 40/70 (57%); P ¼ 0.04); infant not covered in swaddling cloths when exposed to sunlight before crawling (cases 11/52 (21%), controls 25/54 (46%); P ¼ 0.006); and serum 25OHD3 422.5 nmol/l (cases 16/80 (20%), controls 48/70 (69%); Po0.001). In multivariate analysis, factors associated with significantly lower odds ratio for having severe ALRI were: serum 25OHD3 422.5 nmol/l (OR: 0.09; 95% CI 0.03–0.24; Po0.001) and exclusive breastfeeding in the first 4 months of life (OR 0.42; 95% CI 0.18–0.99; P ¼ 0.046) with age and height/age as significant covariates.
Conclusion:
Subclinical vitamin D deficiency and nonexclusive breastfeeding in the first 4 months of life were significant risk factors for severe ALRI in Indian children”
Links
https://www.ncbi.nlm.nih.gov/pubmed/15042122
Citation
Wayse, V., A. Yousafzai, K. Mogale, and S. Filteau. "Association of Subclinical Vitamin D Deficiency with Severe Acute Lower Respiratory Infection in Indian Children under 5 Y." European Journal of Clinical Nutrition 58.4 (2004): 563-67.
“Objectives:
To determine whether subclinical vitamin D deficiency in Indian children under 5 y of age is a risk factor for severe acute lower respiratory infection (ALRI). Design: A hospital-based case-control study. Setting: Sanjeevani Paediatrics Hospital, a private hospital in Indapur, India.
Participants:
A total of 150 children including 80 cases and 70 controls, aged 2–60 months, were enrolled. Case definition of severe ALRI as given by the World Health Organization was used for cases. Controls were healthy children attending outpatients’ service for immunization. Main outcome measure: Association of serum 25-hydroxyvitamin D3 (25OHD3) with severe ALRI, controlling for demographic and other potential risk factors.
Results:
Serum 25OHD3 increased with age. Factors significantly associated with decreased risk of severe ALRI in univariate analysis were: exclusive breastfeeding in the first 4 months (cases 35/78 (45%), controls 41/64 (64%); P ¼ 0.02); introduction of other dietary liquids than milk only after 6 months (cases 46/70 (66%), controls 31/66 (47%); P ¼ 0.03); use of liquid petroleum cooking fuel (cases 32/80 (40%), controls 40/70 (57%); P ¼ 0.04); infant not covered in swaddling cloths when exposed to sunlight before crawling (cases 11/52 (21%), controls 25/54 (46%); P ¼ 0.006); and serum 25OHD3 422.5 nmol/l (cases 16/80 (20%), controls 48/70 (69%); Po0.001). In multivariate analysis, factors associated with significantly lower odds ratio for having severe ALRI were: serum 25OHD3 422.5 nmol/l (OR: 0.09; 95% CI 0.03–0.24; Po0.001) and exclusive breastfeeding in the first 4 months of life (OR 0.42; 95% CI 0.18–0.99; P ¼ 0.046) with age and height/age as significant covariates.
Conclusion:
Subclinical vitamin D deficiency and nonexclusive breastfeeding in the first 4 months of life were significant risk factors for severe ALRI in Indian children”
Links
https://www.ncbi.nlm.nih.gov/pubmed/15042122
Citation
Wayse, V., A. Yousafzai, K. Mogale, and S. Filteau. "Association of Subclinical Vitamin D Deficiency with Severe Acute Lower Respiratory Infection in Indian Children under 5 Y." European Journal of Clinical Nutrition 58.4 (2004): 563-67.
5. Influenza, solar radiation and vitamin D
Abstract
“The annual death numbers of influenza and pneumonia in Norway were studied for the time period 1980–2000. No direct relationships were found with the variations of the annual UVB fluences, probably due to the fact that these variations did not exceed 30%. However, there was a very pronounced seasonal variation of both influenza deaths and pneumonia deaths, the vast majority occurring during the winter. Vitamin D levels were also estimated from several publications. The data support the hypothesis that a high vitamin D level, as that found in the summer, acts in a protective manner with respect to influenza as well as pneumonia. The findings are discussed and compared with data from tropical and subtropical areas”
Links
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3092571/
Citation
Moan, Johan E., Arne Dahlback, Liwei Ma, and Asta Juzeniene. "Influenza, Solar Radiation and Vitamin D." Dermato-Endocrinology 1.6 (2009): 308-10.
“The annual death numbers of influenza and pneumonia in Norway were studied for the time period 1980–2000. No direct relationships were found with the variations of the annual UVB fluences, probably due to the fact that these variations did not exceed 30%. However, there was a very pronounced seasonal variation of both influenza deaths and pneumonia deaths, the vast majority occurring during the winter. Vitamin D levels were also estimated from several publications. The data support the hypothesis that a high vitamin D level, as that found in the summer, acts in a protective manner with respect to influenza as well as pneumonia. The findings are discussed and compared with data from tropical and subtropical areas”
Links
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3092571/
Citation
Moan, Johan E., Arne Dahlback, Liwei Ma, and Asta Juzeniene. "Influenza, Solar Radiation and Vitamin D." Dermato-Endocrinology 1.6 (2009): 308-10.
6. Low Serum 25-Hydroxyvitamin D Level and Risk of Upper Respiratory Tract Infection in Children and Adolescents
Abstract
“Background
Vitamin D may be important for immune function. Studies to date have shown an inconsistent association between vitamin D and infection with respiratory viruses. The purpose of this study was to determine if serum 25-hydroxyvitamin D (25(OH)D) was associated with laboratory-confirmed viral respiratory tract infections (RTIs) in children.
Methods
Serum 25(OH)D levels were measured at baseline and children from Canadian Hutterite communities were followed prospectively during the respiratory virus season. Nasopharyngeal specimens were obtained if symptoms developed and infections were confirmed using polymerase chain reaction. The association between serum 25(OH)D and time to laboratory-confirmed viral RTI was evaluated using a Cox proportional hazards model.
Results
Seven hundred forty-three children aged 3–15 years were followed between 22 December 2008 and 23 June 2009. The median serum 25(OH)D level was 62.0 nmol/L (interquartile range, 51.0–74.0). A total of 229 participants (31%) developed at least 1 laboratory-confirmed viral RTI. Younger age and lower serum 25(OH)D levels were associated with increased risk of viral RTI. Serum 25(OH)D levels”
Links
https://www.ncbi.nlm.nih.gov/pubmed/23677871
Citation
Science, M., J. L. Maguire, M. L. Russell, M. Smieja, S. D. Walter, and M. Loeb. "Low Serum 25-Hydroxyvitamin D Level and Risk of Upper Respiratory Tract Infection in Children and Adolescents." Clinical Infectious Diseases 57.3 (2013): 392-97.
“Background
Vitamin D may be important for immune function. Studies to date have shown an inconsistent association between vitamin D and infection with respiratory viruses. The purpose of this study was to determine if serum 25-hydroxyvitamin D (25(OH)D) was associated with laboratory-confirmed viral respiratory tract infections (RTIs) in children.
Methods
Serum 25(OH)D levels were measured at baseline and children from Canadian Hutterite communities were followed prospectively during the respiratory virus season. Nasopharyngeal specimens were obtained if symptoms developed and infections were confirmed using polymerase chain reaction. The association between serum 25(OH)D and time to laboratory-confirmed viral RTI was evaluated using a Cox proportional hazards model.
Results
Seven hundred forty-three children aged 3–15 years were followed between 22 December 2008 and 23 June 2009. The median serum 25(OH)D level was 62.0 nmol/L (interquartile range, 51.0–74.0). A total of 229 participants (31%) developed at least 1 laboratory-confirmed viral RTI. Younger age and lower serum 25(OH)D levels were associated with increased risk of viral RTI. Serum 25(OH)D levels”
Links
https://www.ncbi.nlm.nih.gov/pubmed/23677871
Citation
Science, M., J. L. Maguire, M. L. Russell, M. Smieja, S. D. Walter, and M. Loeb. "Low Serum 25-Hydroxyvitamin D Level and Risk of Upper Respiratory Tract Infection in Children and Adolescents." Clinical Infectious Diseases 57.3 (2013): 392-97.
7. Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren
Abstract
“Background:
To our knowledge, no rigorously designed clinical trials have evaluated the relation between vitamin D and physiciandiagnosed seasonal influenza.
Objective:
We investigated the effect of vitamin D supplements on the incidence of seasonal influenza A in schoolchildren.
Design:
From December 2008 through March 2009, we conducted a randomized, double-blind, placebo-controlled trial comparing vitamin D3 supplements (1200 IU/d) with placebo in schoolchildren. The primary outcome was the incidence of influenza A, diagnosed with influenza antigen testing with a nasopharyngeal swab specimen.
Results:
Influenza A occurred in 18 of 167 (10.8%) children in the vitamin D3 group compared with 31 of 167 (18.6%) children in the placebo group [relative risk (RR), 0.58; 95% CI: 0.34, 0.99; P = 0.04]. The reduction in influenza A was more prominent in children who had not been taking other vitamin D supplements (RR: 0.36; 95% CI: 0.17, 0.79; P = 0.006) and who started nursery school after age 3 y (RR: 0.36; 95% CI: 0.17, 0.78; P = 0.005). In children with a previous diagnosis of asthma, asthma attacks as a secondary outcome occurred in 2 children receiving vitamin D3 compared with 12 children receiving placebo (RR: 0.17; 95% CI: 0.04, 0.73; P = 0.006).
Conclusion:
This study suggests that vitamin D3 supplementation during the winter may reduce the incidence of influenza A, especially in specific subgroups of schoolchildren”
Links
https://www.ncbi.nlm.nih.gov/pubmed/20219962
Citation
Urashima, M., T. Segawa, M. Okazaki, M. Kurihara, Y. Wada, and H. Ida. "Randomized Trial of Vitamin D Supplementation to Prevent Seasonal Influenza A in Schoolchildren." American Journal of Clinical Nutrition 91.5 (2010): 1255-260.
“Background:
To our knowledge, no rigorously designed clinical trials have evaluated the relation between vitamin D and physiciandiagnosed seasonal influenza.
Objective:
We investigated the effect of vitamin D supplements on the incidence of seasonal influenza A in schoolchildren.
Design:
From December 2008 through March 2009, we conducted a randomized, double-blind, placebo-controlled trial comparing vitamin D3 supplements (1200 IU/d) with placebo in schoolchildren. The primary outcome was the incidence of influenza A, diagnosed with influenza antigen testing with a nasopharyngeal swab specimen.
Results:
Influenza A occurred in 18 of 167 (10.8%) children in the vitamin D3 group compared with 31 of 167 (18.6%) children in the placebo group [relative risk (RR), 0.58; 95% CI: 0.34, 0.99; P = 0.04]. The reduction in influenza A was more prominent in children who had not been taking other vitamin D supplements (RR: 0.36; 95% CI: 0.17, 0.79; P = 0.006) and who started nursery school after age 3 y (RR: 0.36; 95% CI: 0.17, 0.78; P = 0.005). In children with a previous diagnosis of asthma, asthma attacks as a secondary outcome occurred in 2 children receiving vitamin D3 compared with 12 children receiving placebo (RR: 0.17; 95% CI: 0.04, 0.73; P = 0.006).
Conclusion:
This study suggests that vitamin D3 supplementation during the winter may reduce the incidence of influenza A, especially in specific subgroups of schoolchildren”
Links
https://www.ncbi.nlm.nih.gov/pubmed/20219962
Citation
Urashima, M., T. Segawa, M. Okazaki, M. Kurihara, Y. Wada, and H. Ida. "Randomized Trial of Vitamin D Supplementation to Prevent Seasonal Influenza A in Schoolchildren." American Journal of Clinical Nutrition 91.5 (2010): 1255-260.
8. REVIEW ARTICLE: Epidemic influenza and vitamin D
Abstract
“In 1981, R. Edgar Hope-Simpson proposed that a ‘ seasonal stimulus’ intimately associated with solar radiation explained the remarkable seasonality of epidemic influenza. Solar radiation triggers robust seasonal vitamin D production in the skin; vitamin D deficiency is common in the winter, and activated vitamin D, 1,25(OH)2D, a steroid hormone, has profound effects on human immunity. 1,25(OH)2D acts as an immune system modulator, preventing excessive expression of inflammatory cytokines and increasing the ‘oxidative burst’ potential of macrophages. Perhaps most importantly, it dramatically stimulates the expression of potent anti-microbial peptides, which exist in neutrophils, monocytes, natural killer cells, and in epithelial cells lining the respiratory tract where they play a major role in protecting the lung from infection. Volunteers inoculated with live attenuated influenza virus are more likely to develop fever and serological evidence of an immune response in the winter. Vitamin D deficiency predisposes children to respiratory infections. Ultraviolet radiation (either from artificial sources or from sunlight) reduces the incidence of viral respiratory infections, as does cod liver oil (which contains vitamin D). An interventional study showed that vitamin D reduces the incidence of respiratory infections in children. We conclude that vitamin D, or lack of it, may be Hope-Simpson’s ‘ seasonal stimulus’”
Links
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2870528/
Citation
Cannell, J. J., R. Vieth, J. C. Umhau, M. F. Holick, W. B. Grant, S. Madronich, C. F. Garland, and E. Giovannucci. "Epidemic Influenza and Vitamin D." Epidemiology and Infection 134.06 (2006): 1129.
“In 1981, R. Edgar Hope-Simpson proposed that a ‘ seasonal stimulus’ intimately associated with solar radiation explained the remarkable seasonality of epidemic influenza. Solar radiation triggers robust seasonal vitamin D production in the skin; vitamin D deficiency is common in the winter, and activated vitamin D, 1,25(OH)2D, a steroid hormone, has profound effects on human immunity. 1,25(OH)2D acts as an immune system modulator, preventing excessive expression of inflammatory cytokines and increasing the ‘oxidative burst’ potential of macrophages. Perhaps most importantly, it dramatically stimulates the expression of potent anti-microbial peptides, which exist in neutrophils, monocytes, natural killer cells, and in epithelial cells lining the respiratory tract where they play a major role in protecting the lung from infection. Volunteers inoculated with live attenuated influenza virus are more likely to develop fever and serological evidence of an immune response in the winter. Vitamin D deficiency predisposes children to respiratory infections. Ultraviolet radiation (either from artificial sources or from sunlight) reduces the incidence of viral respiratory infections, as does cod liver oil (which contains vitamin D). An interventional study showed that vitamin D reduces the incidence of respiratory infections in children. We conclude that vitamin D, or lack of it, may be Hope-Simpson’s ‘ seasonal stimulus’”
Links
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2870528/
Citation
Cannell, J. J., R. Vieth, J. C. Umhau, M. F. Holick, W. B. Grant, S. Madronich, C. F. Garland, and E. Giovannucci. "Epidemic Influenza and Vitamin D." Epidemiology and Infection 134.06 (2006): 1129.
9. Serum 25-Hydroxyvitamin D and the Incidence of Acute Viral Respiratory Tract Infections in Healthy Adults
Abstract
“Background:
Declining serum concentrations of 25-hydroxyvitamin D seen in the fall and winter as distance increases from the equator may be a factor in the seasonal increased prevalence of influenza and other viral infections. This study was done to determine if serum 25-hydroxyvitamin D concentrations correlated with the incidence of acute viral respiratory tract infections.
Methodology/Findings:
In this prospective cohort study serial monthly concentrations of 25-hydroxyvitamin D were measured over the fall and winter 2009–2010 in 198 healthy adults, blinded to the nature of the substance being measured. The participants were evaluated for the development of any acute respiratory tract infections by investigators blinded to the 25-hydroxyvitamin D concentrations. The incidence of infection in participants with different concentrations of vitamin D was determined. One hundred ninety-five (98.5%) of the enrolled participants completed the study. Light skin pigmentation, lean body mass, and supplementation with vitamin D were found to correlate with higher concentrations of 25-hydroxyvitamin D. Concentrations of 38 ng/ml or more were associated with a significant (p,0.0001) two-fold reduction in the risk of developing acute respiratory tract infections and with a marked reduction in the percentages of days ill.
Conclusions/Significance:
Maintenance of a 25-hydroxyvitamin D serum concentration of 38 ng/ml or higher should significantly reduce the incidence of acute viral respiratory tract infections and the burden of illness caused thereby, at least during the fall and winter in temperate zones. The findings of the present study provide direction for and call for future interventional studies examining the efficacy of vitamin D supplementation in reducing the incidence and severity of specific viral infections, including influenza, in the general population and in subpopulations with lower 25-hydroxyvitamin D concentrations, such as pregnant women, dark skinned individuals, and the obese”
Links
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0011088
Citation
Sabetta, James R., Paolo Depetrillo, Ralph J. Cipriani, Joanne Smardin, Lillian A. Burns, and Marie L. Landry. "Serum 25-Hydroxyvitamin D and the Incidence of Acute Viral Respiratory Tract Infections in Healthy Adults." PLoS ONE 5.6 (2010)
“Background:
Declining serum concentrations of 25-hydroxyvitamin D seen in the fall and winter as distance increases from the equator may be a factor in the seasonal increased prevalence of influenza and other viral infections. This study was done to determine if serum 25-hydroxyvitamin D concentrations correlated with the incidence of acute viral respiratory tract infections.
Methodology/Findings:
In this prospective cohort study serial monthly concentrations of 25-hydroxyvitamin D were measured over the fall and winter 2009–2010 in 198 healthy adults, blinded to the nature of the substance being measured. The participants were evaluated for the development of any acute respiratory tract infections by investigators blinded to the 25-hydroxyvitamin D concentrations. The incidence of infection in participants with different concentrations of vitamin D was determined. One hundred ninety-five (98.5%) of the enrolled participants completed the study. Light skin pigmentation, lean body mass, and supplementation with vitamin D were found to correlate with higher concentrations of 25-hydroxyvitamin D. Concentrations of 38 ng/ml or more were associated with a significant (p,0.0001) two-fold reduction in the risk of developing acute respiratory tract infections and with a marked reduction in the percentages of days ill.
Conclusions/Significance:
Maintenance of a 25-hydroxyvitamin D serum concentration of 38 ng/ml or higher should significantly reduce the incidence of acute viral respiratory tract infections and the burden of illness caused thereby, at least during the fall and winter in temperate zones. The findings of the present study provide direction for and call for future interventional studies examining the efficacy of vitamin D supplementation in reducing the incidence and severity of specific viral infections, including influenza, in the general population and in subpopulations with lower 25-hydroxyvitamin D concentrations, such as pregnant women, dark skinned individuals, and the obese”
Links
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0011088
Citation
Sabetta, James R., Paolo Depetrillo, Ralph J. Cipriani, Joanne Smardin, Lillian A. Burns, and Marie L. Landry. "Serum 25-Hydroxyvitamin D and the Incidence of Acute Viral Respiratory Tract Infections in Healthy Adults." PLoS ONE 5.6 (2010)
10. Vitamin D and Respiratory Tract Infections: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Abstract
“Background:
Low levels of 25-OH vitamin D are associated with respiratory tract infection (RTI). However, results from randomized controlled trials are inconclusive. Therefore, we performed a systematic review and meta-analysis to assess the preventive effect of vitamin D supplementation on RTI.
Methods:
Randomized, controlled trials of vitamin D for prevention of RTI were used for the analysis. The risks of within-trial and publication bias were assessed. Odds ratios of RTI were pooled using a random-effects model. Heterogeneity was assessed using Cochran’s Q and I2 . Meta-regressions and subgroup analyses were used to assess the influence of various factors on trial outcome. The pre-defined review protocol was registered at the PROSPERO international prospective register of systematic reviews, registration number CRD42013003530.
Findings:
Of 1137 citations retrieved, 11 placebo-controlled studies of 5660 patients were included in the meta-analysis. Overall, vitamin D showed a protective effect against RTI (OR, 0.64; 95% CI, 0.49 to 0.84). There was significant heterogeneity among studies (Cohran’s Q p,0.0001, I2 = 72%). The protective effect was larger in studies using once-daily dosing compared to bolus doses (OR = 0.51 vs OR = 0.86, p = 0.01). There was some evidence that results may have been influenced by publication bias.
Interpretation:
Results indicate that vitamin D has a protective effect against RTI, and dosing once-daily seems most effective. Due to heterogeneity of included studies and possible publication bias in the field, these results should be interpreted with caution”
Links
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0065835
Citation:
“Bergman, Peter, U. Lindh, Linda Brkhem-Bergman, and Jonatan D. Lindh. "Vitamin D and Respiratory Tract Infections: A Systematic Review and Meta-Analysis of Randomized Controlled Trials." PLoS ONE 8.6 (2013)”
“Background:
Low levels of 25-OH vitamin D are associated with respiratory tract infection (RTI). However, results from randomized controlled trials are inconclusive. Therefore, we performed a systematic review and meta-analysis to assess the preventive effect of vitamin D supplementation on RTI.
Methods:
Randomized, controlled trials of vitamin D for prevention of RTI were used for the analysis. The risks of within-trial and publication bias were assessed. Odds ratios of RTI were pooled using a random-effects model. Heterogeneity was assessed using Cochran’s Q and I2 . Meta-regressions and subgroup analyses were used to assess the influence of various factors on trial outcome. The pre-defined review protocol was registered at the PROSPERO international prospective register of systematic reviews, registration number CRD42013003530.
Findings:
Of 1137 citations retrieved, 11 placebo-controlled studies of 5660 patients were included in the meta-analysis. Overall, vitamin D showed a protective effect against RTI (OR, 0.64; 95% CI, 0.49 to 0.84). There was significant heterogeneity among studies (Cohran’s Q p,0.0001, I2 = 72%). The protective effect was larger in studies using once-daily dosing compared to bolus doses (OR = 0.51 vs OR = 0.86, p = 0.01). There was some evidence that results may have been influenced by publication bias.
Interpretation:
Results indicate that vitamin D has a protective effect against RTI, and dosing once-daily seems most effective. Due to heterogeneity of included studies and possible publication bias in the field, these results should be interpreted with caution”
Links
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0065835
Citation:
“Bergman, Peter, U. Lindh, Linda Brkhem-Bergman, and Jonatan D. Lindh. "Vitamin D and Respiratory Tract Infections: A Systematic Review and Meta-Analysis of Randomized Controlled Trials." PLoS ONE 8.6 (2013)”