This article is more than 5 years old. Information may no longer be current.
Supplemental vitamin D may reduce incidence of common cold
Vitamin D supplementation decreased the risk for respiratory infections in a group of Mongolian schoolchildren, according to study results published online.
Carlos Camargo, MD, of Massachusetts General Hospital, and colleagues conducted a masked study to assess the number of winter respiratory infections among a group of 247 Mongolian children. One hundred forty-three children received daily doses (300 IU) of vitamin D added to locally produced milk compared with a control group of children (n=104) who received the same milk without added vitamin D.
Although blood samples taken at the outset of the study revealed vitamin D deficiency in all participants, with average 25-hydroxyvitamin D levels of about 7 ng/mL (17 nmol/L) in both groups, at the end of the 7-week treatment period, differences between the two groups were significant. Children who received 25-hydroxyvitamin D averaging 19 ng/mL (47 nmol/L), although still low, was significantly higher compared with the start of the trial. Based on reports from their parents, the children in the vitamin D group had about half the incidence of respiratory infections reported in the control group.
“Our study design provides strong evidence that the association between low vitamin D and respiratory infections is causal and that treating low vitamin D levels in children with an inexpensive and safe supplement will prevent some respiratory infections,” Camargo said in a press release. “The large benefit was undoubtedly related to the low baseline vitamin D levels of these children, so I would not expect the supplement to provide similar benefit in children who start with healthy levels of vitamin D. The key question for future research is at what initial vitamin D level would children no longer receive benefit from winter supplementation?”
Disclosure: The researchers report no relevant financial disclosures.
