A common question many women have is whether an extra dose of calcium and vitamin D is necessary during pregnancy and breastfeeding. Additionally, many breastfeeding women wonder if consuming milk is essential to produce breast milk. The good news is that the answer is no!  

Vitamin D and Calcium During Pregnancy

It might seem surprising that the recommended average daily intake for calcium and vitamin D remains largely unchanged during pregnancy and lactation despite the increased demand to support both your bone health and your growing baby's needs.  

This is because your body becomes much more efficient at absorbing calcium during pregnancy, especially in the latter half when your baby grows the fastest. Specifically, calcium absorption in your digestive tract can increase from about 35% before pregnancy to about 60% during pregnancy. Furthermore, blood levels of vitamin D can rise by 50-100% over non-pregnant levels, possibly due to actions of the placenta.

Daily Recommendations

To meet the recommended daily intakes of 1000 mg of calcium and 600 IU of vitamin D during pregnancy (400 IU of vitamin D is needed during breastfeeding), focus on consuming nutrient-rich foods. These include milk, dairy products, low-mercury fatty fish, and fortified orange juice and cereals. Additionally, a prenatal vitamin generally contains about 250 mg of calcium and 400 IU of vitamin D. For women under eighteen years of age, the recommended daily calcium intake is slightly higher at 1300 mg.

A separate calcium supplement might be necessary if you find it challenging to include enough calcium-rich foods in your diet. Since only 500 mg of calcium can be absorbed at one time, consider taking another 500 or 600 mg supplement at a different time from your prenatal vitamin. 

Calcium citrate tends to be better absorbed than calcium carbonate because it doesn't require stomach acid to be broken down. If you choose calcium carbonate, make sure to take it with a meal to aid in its breakdown. Also, remember to separate your calcium supplements from iron supplements, as these minerals can interfere with each other's absorption. If you're following a vegan diet, you might need an additional daily vitamin D supplement of about 200 IU, as it can be difficult to obtain adequate amounts of this vitamin through food alone.

Sources:

• Specker, Bonny. "Vitamin D requirements during pregnancy." American Journal of Clinical Nutrition. December 2004, vol. 80. Web. 26 Sept 2013.
• "Dietary Supplement Fact Sheet: Vitamin D." Office of Dietary Supplements. National Institutes of Health. 24 Jun 2011. Web. 26 Sept 2013.