Nutrition Science and Everyday Application - beta v 0.1

VITAMIN D: IMPORTANT TO BONE HEALTH AND BEYOND 519
beverages, and breakfast cereal can all contribute to dietary intake of vitamin D, although
amounts added vary significantly between products. 2
Figure 9.12. Dietary sources of vitamin D. Source: Examples of good sources pictured include
salmon, milk, mushrooms, fortified soy milk, and fortified cereal. NIH Office of Dietary
Supplements
Both vitamin D 2 and D 3 supplements are also available. Some studies have found D 3 to be
more effective at raising circulating vitamin D levels, but others haven’t found a difference in
efficacy of the two forms. 1,2 Human breast milk doesn’t contain adequate vitamin D, so the
American Academy of Pediatrics recommends that breastfed infants receive a supplement
with 400 IU of vitamin D per day until they are weaned to vitamin D-fortified formula or
cow’s milk. A vitamin D supplement may also be recommended for older children and
adults, depending on dietary intake and sun exposure, but this should be discussed with a
healthcare provider.
VITAMIN D DEFICIENCY AND TOXICITY
In children, vitamin D deficiency causes rickets, a disease in which the bones are soft, weak,
and deformed. Rickets was very common in the U.S. until the 1930s, when milk processors
were asked to add vitamin D to cow’s milk. Milk fortification has virtually eliminated rickets
from the U.S. and other developed countries. However, rickets does still occur in breastfed
infants and children raised on vegan diets who aren’t provided with other sources of vitamin
D, particularly if they have darker skin pigmentation. 1,3