Vitamin D for treatment and prevention of infectious diseases: a systematic review of randomized controlled trials.
OBJECTIVE
To review the existing human controlled intervention studies of vitamin D as adjunctive therapy in settings of infection and provide recommendations for design and implementation of future studies in this field on the basis of the evidence reviewed.


METHODS
We conducted a systematic review of randomized controlled clinical trials that studied vitamin D for treatment or prevention of infectious diseases in humans. Studies from 1948 through 2009 were identified through search terms in PubMed and Ovid MEDLINE.


RESULTS
Thirteen published controlled trials were identified by our search criteria. Ten trials were placebo controlled, and 9 of the 10 were conducted in a rigorous double-blind design. The selected clinical trials demonstrated substantial heterogeneity in baseline patient demographics, sample size, and vitamin D intervention strategies. Serious adverse events attributable to vitamin D supplementation were rare across all studies. On the basis of studies reviewed to date, the strongest evidence supports further research into adjunctive vitamin D therapy for tuberculosis, influenza, and viral upper respiratory tract illnesses. In the selected studies, certain aspects of study design are highlighted to help guide future clinical research in the field.


CONCLUSIONS
More rigorously designed clinical trials are needed for further evaluation of the relationship between vitamin D status and the immune response to infection as well as for delineation of necessary changes in clinical practice and medical care of patients with vitamin D deficiency in infectious disease settings.
Yamshchikov
Alexandra V
AV
Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia 30030, USA. AYAMSHC@emory.edu
Desai
Nirali S
NS
Blumberg
Henry M
HM
Ziegler
Thomas R
TR
Tangpricha
Vin
V
D003141:Communicable Diseases / Q000188:drug therapy* / Q000382:microbiology / Q000635:transmission / Q000821:virology; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D014807:Vitamin D / Q000627:therapeutic use*; D014808:Vitamin D Deficiency / Q000150:complications / Q000517:prevention & control
D014807:Vitamin D