A Healthy Pregnancy
Vitamin D Supplements in Pregnancy and Breastfeeding

Browse any health website or magazine and you are likely to see something about vitamin D. Vitamin D is a fat soluble vitamin that is essential for the absorption of calcium and for bone health. It is also important for cell health, the immune system and neuromuscular function. Recent studies have indicated that adequate levels of vitamin D may reduce the risk of other diseases including cancers, rheumatoid arthritis, type 1 diabetes, immune disorders, and other health condition. Vitamin D is essential in cell growth, strengthens bones, and is important to the immune system.

A recent nationwide survey indicated that 41 percent of men and 53 percent of women are deficient in vitamin D. These numbers may be increasing. 1, 2 But it isn't just older adults. Many nursing mothers, their infants, and a number of US children have inadequate levels of vitamin D. 3, 4 Vitamin D deficiency can have serious implications for a child's health, including development of rickets, a higher risk of asthma, bone problems, and possible immune diseases.

Most people get much of their vitamin D through sunshine exposure. However, the increasing use of sunscreen, along with lives that are lived indoors, has decreased the amount of vitamin D from this source. This is especially true for dark skinned people (who require significantly more sun exposure to make the same amount of vitamin D). Vitamin D is naturally present in only a small percentage of food but is added to others, most notably milk. Vitamin D fortified milk was introduced to help prevent rickets in children (a disease where the bones are soft because they do not mineralize properly, which causes skeletal deformities). Rickets had mostly disappeared in the US but is now reappearing.

Vitamin D is a fat soluble vitamin, which means that the body stores "extra" amounts. Because of this, nutritionists have recommended not exceeding the recommended daily allowance (200 IU for young adults) to avoid toxicity. However, the recommended daily allowance is under dispute. The Institute of Medicine asserts that 1000 IU daily is a better recommended daily allowance and that the safe upper limit for vitamin D is 2,000 IUs for children, adults, and pregnant and lactating women. 5

"It is recommended that pregnant and nursing mothers obtain adequate vitamin D or supplement as necessary."
– La Leche League International

Although the form of vitamin D in breast milk is readily absorbed, breast milk is low in vitamin D. Many experts recommend that breastfeeding infants receive vitamin D supplements. In 2008 the American Academy of Pediatrics doubled the amount of vitamin D they recommend for infants, raising it to 400 IU daily.

Vitamin D supplementation for breastfeeding babies has been discouraged by many breastfeeding advocates who state that exclusive breastfeeding should be that – only breastmilk. However, La Leche League, a leader in breastfeeding advocacy and education, in 2008, while reaffirming a belief in the adequacy of breastmilk alone, gave the disclaimer that breastmilk only provided enough vitamin D for babies if the mothers themselves had adequate vitamin D.

A woman's vitamin D status during pregnancy does make a difference in baby's status at birth. A woman's vitamin D status during lactation also makes a difference in her breastmilk. The amount of vitamin D that mom transfers to baby before birth appears to be more significant than transfer in early breastfeeding.6

Adequate vitamin D is important for pregnant women in other ways as well. Vitamin D insufficiency is associated with a higher incidence of bacterial vaginosis, the most common vaginal infection in US women of childbearing age. BV can cause preterm delivery.7 Recent research indicates that vitamin D may help the placenta to fight off a number of disease causing organisms, including styphylococcus, streptococcus, and E. coli bacteria.8

These findings would indicate that a vitamin D supplement may indeed be a good idea. How much should you take? That is the difficult question, and the answer is not "one size fits all."

Variables include :

  • Your current vitamin D status (which can be measured by a lab test)
  • Whether your skin is light or dark
  • The amount of sunshine you receives (also how much pollution is in the air)
  • The amount of sunscreen you wear

Other considerations:

  • The Norwegian study recommended at least 10 mcg/day and did not find any further reductions in preeclampsia rates after 20 mcg/day.
  • The current RDA for vitamin D in the US is 200-400IU (5-10 mcg) for pregnant women.
  • The Institute of Medicine suggests that 1000IU (25 mcg) is a better level and that 2000IU (50 mcg) is the safe upper limit.

Consider your individual circumstances, talk to your physician about your risk factors, and then make your best choice.

Nourish yourself and your child!

Note: Vitamin D is measured both in micrograms as well as international units (IU). 5 mcg =200 IU
The current US RDA for pregnant women is 200-400 IU (or 5-10 mcg) daily; The Institute of Medicine has recommended 1000 IU (25 mcg)

1. http://www.sciencedaily.com/releases/2008/08/080811195629.htm
2. http://www.sciencedaily.com/releases/2009/06/090630143523.htm
3. Women, infants: http://www.sciencedaily.com/releases/2008/12/081216161058.htm
4. Children: http://www.cnn.com/2009/HEALTH/08/03/vitamin.d.children/
5. http://www.webmd.com/food-recipes/features/are-you-getting-enough-vitamin-d?page=2
6. http://www.cdc.gov/nccdphp/dnpa/nutrition/pdf/
Vitamin_D_Expert_Panel_Meeting.pdf
7. http://www.sciencedaily.com/releases/2009/05/090514111414.htm
8. http://www.sciencedaily.com/releases/2008/12/081201162125.htm