Vitamin D During Pregnancy

Though many are now recognizing the high rate of vitamin D deficiency in the United States, some groups still may not be taking enough.  New research suggests high amounts of vitamin D supplementation may be particularly important during pregnancy and lactation.

Supplementation is necessary not just for the mother, but also to ensure the infant is getting enough.  Adequate vitamin D levels have been associated with regulating the immune system, building strong bones, preventing rickets and even reducing the risk of asthma.  Furthermore, taking high amounts of vitamin D during pregnancy has been shown to reduce complications during pregnancy.

In one study , presented at the 2010 Pediatric Academic Societies Annual Meeting, pregnant women were divided into three groups that received either 400, 2,000 or 4,000 IU of vitamin D daily, from the time they were three months pregnant through delivery.  Researchers found that taking 4,000 IU (about 10 times the amount normally recommended) cut the rate of pregnancy-related complications (including gestational diabetes, high blood pressure, preeclampsia and premature birth) in half when compared to the women who took just 400 IU per day.

While it’s true that infants only need about 400 IU of vitamin D per day to prevent deficiency, nursing women may require several thousand IU’s of vitamin D for 400 to pass through the breast milk.  Current research has shown that the actual dietary requirement during pregnancy and lactation may even be as high as 6000 IU/day.

Pregnant/lactating women aren’t the only group that may need several thousand IU’s of Vitamin D.  Obese individuals have a decreased ability to make vitamin D.  In addition, those with dark skin are also at a higher deficiency risk, because it’s harder for highly pigmented skin to manufacturer D from the sun.  Getting little sun exposure or always wearing sun block may also put you at risk.

To ensure you are getting enough vitamin D:

• Try to get 15 minutes of sun exposure (with out sun block) several days a week.
• Consider supplementation in the form of D3 or cholecalciferol for best absorption. (D2 or ergocalciferol is not as good of a form).  If your supplement bottle doesn’t say on the front, try turning the label around.  It should specify the form under the supplement fact label.
• Though food sources aren’t usually enough to raise blood levels of D, fatty fish such as salmon or mackerel and fortified orange juice and milk are the best food sources.
• If you are concerned about your D levels, consider having a Spectracell Micronutrient test.  This blood test actually looks in the white blood cells vs. serum blood levels to obtain a history of deficiency rather than just a snapshot.

–Nicole Gould, RD LD