The American Journal of Obstetrics and Gynecology published an article in the May 2010 edition that is noteworthy of discussion. Although vitamin D has been around since time immemorial, recent studies have suggested that the American intake is insufficient. Although the Recommended Dietary Allowances (RDA) originally suggested a daily intake of 200 International Units (IU) until age 50 and 400 IU thereafter, these recommendations might change in the near future.
Vitamin D is fat soluble and is important in the metabolism of calcium. For pregnant women calcium is extremely important because it supports the developing fetal skeleton. Sun exposure, skin pigmentation, diet and obesity can affect the amount of vitamin D that one receives. In the United States, vitamin D deficiency is estimated to occur in 5-50% of pregnant women. Why is this important? Because vitamin D deficiency has been associated with an increased risk of pre-eclampsia, bone loss, poor weight gain, gestational diabetes and small babies. African American women also have a higher incidence of vitamin D deficiency because of their increased pigment. Breast-fed babies from vitamin D deficient mothers may occasionally exhibit life-threatening conditions such as seizures and enlarged hearts (aka dilated cardiomyopathy). In the third trimester, the demand for calcium increases for the fetus because of the mineralization of its skeleton.
In November of 2008, the American Academy of Pediatrics recommends that exclusively breast-fed infants receive vitamin supplements that include 400 IU of vitamin D daily from birth until adolescence. Although pregnant women can receive vitamin D through fortified cereals and prenatal vitamins, the 400 IU standard dose might not be enough. At present, prenatal care does not include monitoring vitamin D levels which is unfortunate because a deficiency detected could be easily treated.
Further studies are needed to determine exactly how much vitamin D is really necessary for pregnant women to consume and there are also medical studies that suggest women who desire children begin taking vitamin D a few months before becoming pregnant in order to have sufficient levels in the first trimester. Perhaps it’s time for pregnant women to bring up the discussion of vitamin D supplementation and monitoring during their prenatal visits.
A healthy pregnancy doesn’t just happen. It takes a smart mother who knows what to do.