The majority of science indicates that Vitamin D supplements are associated with a reduced risk of type 1 diabetes in children, an analysis of the medical literature has found.
In a review published in the journal Archives of Disease in Childhood, researchers examined data from five observational studies. After examining the results, the researchers found that infants who received vitamin D supplements were 29 percent less likely to develop type-1 diabetes than non-supplemented infants.
Data was available for 6,455 infants (1,429 cases and 5,026 controls). No randomized controlled trials were found in the literature, so the reviewers analyzed only the five observational studies.
The researchers of the current study also noted some evidence of a dose-response effect, with those using higher amounts of vitamin D at lower risk of developing type 1 diabetes. In addition, timing of supplementation appeared to play a role in type 1 diabetes risk. Infants given vitamin D-rich cod liver oil between the ages of seven and 12 months had a 45 percent lower risk, compared to infants given vitamin D between 0 and six months of age.
The researchers called for randomized, controlled studies to confirm their findings.
Type 1 diabetes occurs when individuals stop producing insulin after the cells in the pancreas have been damaged. The condition is thought to be autoimmune related. Disease incidence is rising at about three percent per year, and the number of new cases of type 1 diabetes is predicted to rise 40 percent between 2000 and 2010.
The mechanism by which vitamin D supplementation may guard against type 1 diabetes is uncertain. However, vitamin D is thought to play a role in immunity and may have a role to play in beta-cell function as well.
Reference:
Zipitis CS, Akobeng AK. Vitamin D supplementation in early childhood and risk of type 1 diabetes: a systematic review and meta-analysis. Archives of Disease in Childhood. 2008 Mar 13. Published online ahead of print.