Toast with avacado and egg on it.
Study shows that women who had sufficient vitamin D levels, were 10 percent more likely to become pregnant and 15 percent more likely to have a live birth than those with lower levels of vitamin D. (For Spectrum Health Beat)

Women who’ve had a miscarriage are more likely to get pregnant and have a baby if they have adequate levels of vitamin D, new research indicates.

“Our findings suggest that vitamin D may play a protective role in pregnancy,” said lead investigator Sunni Mumford, from the epidemiology branch of the U.S. National Institute of Child Health and Human Development.

Previous studies have shown that in vitro fertilization is more successful among women with higher levels of vitamin D, the study authors explained in a news release from the U.S. National Institutes of Health.

But the investigators noted there is little evidence on the link between vitamin D and pregnancy rates/pregnancy loss among women not using reproductive technologies.


Our Take

Discuss your vitamin D level with your OB provider.

The Vitamin D Council recommends 4,000 to 6,000 IU daily, but the Endocrine Society recommends 1,500 to 2,000 IU per day. The Food and Nutrition Board sets it at just 600 IU.

A study by researchers in South Carolina found that a pregnant woman would need 4,000 IU of vitamin D each day to ensure her baby has enough at birth. Interestingly, the study also found that mothers who take 4,000 IU of vitamin D may experience fewer birth complications.

Another study found that a liter of breast milk from a mom who took 6,400 IU of vitamin D daily contained, on average, about 800 IUs of vitamin D. In moms who took 400 IU, a liter of breast milk contained about 50 IUs of the vitamin.

Clearly, mom can help baby if she supplements with vitamin D.

How to get more vitamin D

If you want to boost your vitamin D levels, start with the following food sources:

  • Cereal fortified with vitamin D
  • Beef liver
  • Egg yolks
  • Milk and yogurt fortified with vitamin D
  • Orange juice fortified with vitamin D
  • Tuna, salmon, sardines, mackerel and some other types of fatty fish

You can also increase your vitamin D intake through supplements.

For the study, the researchers examined the vitamin D levels of 1,200 women with a history of miscarriage before they got pregnant again. Their vitamin D levels were also tested when they were eight weeks’ pregnant.

Although it doesn’t prove cause and effect, the study showed that the women who had sufficient vitamin D levels, or concentrations of 30 nanograms per milliliter (ng/mL) or more, were 10 percent more likely to become pregnant and 15 percent more likely to have a live birth than those with lower levels of vitamin D.

Among the women who got pregnant, every 10 ng/mL increase in vitamin D before conception was associated with a 12 percent lower risk of miscarriage. The researchers reported that by the eighth week of pregnancy, vitamin D levels were no longer linked to pregnancy loss.

The findings were published in The Lancet Diabetes & Endocrinology.

The study authors noted that more research is needed to determine if vitamin D supplements could reduce the risk of pregnancy loss among women at high risk for miscarriage.