Vitamin D deficiency is common in Mongolian children. This is partly because of long, cold winters, which limit exposure to the sun for many months of the year, the lack of food fortification, and the limited availability of supplements. Researchers in the United States have found that Mongolian children who drank Vitamin D-fortified milk experienced nearly half the winter colds of those who used unfortified milk. Even in the United States, approximately 20% of children are Vitamin D deficient.
PositiveTip: Adequate exposure to sunlight or Vitamin D supplements might help prevent winter colds in children.