Effect of vitamin D during pregnancy on children 3 years later

Pregnant women who take higher doses of vitamin D might be able to decrease the risk of recurrent wheezing in their offspring, according to this study in The American Journal of Clinical Nutrition.

A questionnaire was used to determine the intake of vitamin D in 1194 women during their pregnancy. At age 3 their offspring were evaluated for recurrent wheezing.

When the lowest and highest intakes of vitamin D were compared, mothers who took the highest daily intake (724 international units [IU]) had a significantly lower risk of having a child with recurrent wheeze compared to those who took the lowest daily amounts (356 IU).

The source of the vitamin D — diet or supplements — had no effect on the outcome.

The researchers concluded that these findings would be most applicable in the northeastern United States, because “vitamin D deficiency and asthma are common at higher latitudes.”

According to the National Institues of Health, the Adequate Intake for vitamin D during pregnancy is just 200 IU per day. Upper tolerable intake is 2000 IU per day. Dietary sources of vitamin D and calcium are listed here.