Vitamin D in pregnancy and breastfeeding

There has been a lot of buzz around Vitamin D in the last few years, and with good reason.  Evidence continues to mount about the importance of getting enough of this vitamin.  While getting enough vitamin D is a concern for everyone, sufficient Vitamin D is especially important during pregnancy, while breastfeeding, and for babies.

Because the body produces Vitamin D via sun exposure, we in the North—with our months of underexposure to sunlight—need to be particularly vigilant about getting enough vitamin D through diet and supplementation.  Foods such as oily fish and eggs provide some vitamin D, though it is not always enough to eat these foods.  Supplementation is often necessary.

We offer blood testing at the center to check for levels of Vitamin D in the blood; and, from this, we are able to recommend an appropriate dosage of D3 supplementation.  We also carry vitamin D supplements at the center.

What is Vitamin D?

Vitamin D promotes calcium absorption in the gut and maintains adequate calcium and phosphate levels to enable healthy bone mineralization and to prevent disease. It is also needed for bone growth and bone remodeling.  Without sufficient vitamin D, bones can become thin, brittle, or deformed. Getting enough Vitamin D prevents rickets in children and a condition called osteomalacia in adults. Together with calcium, vitamin D also helps protect older adults from osteoporosis.

Vitamin D in foods

Very few foods naturally contain vitamin D. The flesh of fatty fish such as salmon, tuna, and mackerel, as well as fish liver oils, are among the best sources.  Of course in pregnancy, it is important to be mindful of safe fish intake to limit mercury exposure.

Small amounts of vitamin D are also found in beef liver, cheese, and egg yolks.  Other foods in the American diet are fortified with vitamin D, such as milk and cereal.

Research on the importance of Vitamin D in pregnancy

Vitamin D and preeclampsia

Women who are deficient in vitamin D in the first 26 weeks of their pregnancy may be at risk of developing severe preeclampsia, a potentially life-threatening disorder diagnosed by an increase in blood pressure and protein in the urine, according to research by the University of Pittsburgh Graduate School of Public Health.  This study found women with Vitamin D sufficiency at a 40% lower risk of severe pre-eclampsia.

Vitamin D and infant brain development

Emerging studies show a strong correlation between mom’s intake of Vitamin D and baby’s physical and cognitive development.  Fetuses use vitamin D in the womb for many important processes including regulation of the metabolism of neurotropic factors and neurotoxins, signaling neuronal differentiation, and protecting the brain from inflammation.

A recent study in Spain showed that the 14-month old children of women with sufficient Vitamin D in pregnancy scored higher on mental and motor skills evaluations, which can be predictive of IQ later in life, compared to babies whose mothers were deficient in Vitamin D during pregnancy.

Other studies have linked insufficient levels of vitamin D during pregnancy with language impairment in children at 5 and 10 years of age.

Prenatal Vitamin D may prevent autism

Researchers are also beginning to understand the link between prenatal Vitamin D levels and autism in children.  This study discusses this link further and mentions high rates of autism among Somali children in Minneapolis whose mothers were deficient in Vitamin D prenatally.

Vitamin D in pregnancy helps baby’s muscle strength

One UK study found that mothers who had high levels of vitamin D had children with a much higher grip strength compared with the children of mothers who had low vitamin D levels.

Dr. Harvey, a researcher in this study, explains:  “Muscle strength peaks in young adulthood before declining in older age and low grip strength in adulthood has been associated with poor health outcomes including diabetes, falls and fractures.

It is likely that the greater muscle strength observed at 4 years of age in children born to mothers with higher vitamin D levels will track into adulthood, and so potentially help to reduce the burden of illness associated with loss of muscle mass in old age.”

Postpartum Depression and Vitamin D

Other studies have found that sufficient Vitamin D intake can reduce the risk of postpartum depression.

Getting enough Vitamin D

It is important for all women in the childbearing cycle from conception planning to postpartum to get enough Vitamin D.  Studies have shown that women who take 4,000 International Units (IUs) of Vitamin D every day have the lowest risks of preterm labor, premature infants, and infection.

We are happy to speak with our clients about optimal Vitamin D supplementation depending on current levels and overall health.  This article also discusses the issue of safe and optimal levels in pregnancy.

Breastfed infants and Vitamin D

The vitamin D content of human milk is related to the mother’s vitamin D status.  The National Instituted of Health recognizes that mothers who supplement with high doses of vitamin D may have correspondingly high levels of this nutrient in their milk.  Generally speaking however, vitamin D requirements cannot ordinarily be met by human milk alone.

While the sun is a potential source of vitamin D for infants, experts caution against direct exposure to sunlight for infants, which reduces their exposure. The American Academy of Pediatrics recommends that exclusively and partially breastfed infants be supplemented with 400 IU of vitamin D daily, which is the RDA for this nutrient during infancy.




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