Low vitamin D levels increase the risk of early miscarriages during the first trimester

This study investigated low vitamin D levels as a risk factor of early miscarriages. Researchers reported that low vitamin D levels increased the risk for miscarriage during the first trimester, but not during the second trimester. 

Miscarriage is reported to occur in about 12 to 20% of pregnancies. There are a number of different causes of miscarriage, including genetic and environmental factors. Some factors can be addressed early to reduce the risk of miscarriage. Increasing evidence is suggesting that low vitamin D levels may have an effect on miscarriage. Vitamin D plays an important role in regulating the immune system. Proper functioning of the immune system is, in turn, important for successful pregnancies. Further studies are needed evaluating the effect of vitamin D levels on the risk of early miscarriages (pregnancy loss before 12 weeks).

The aim of this study was to examine the effect of vitamin D on the risk of early miscarriage. A total of 1,683 pregnant women provided a blood test measuring vitamin D levels before the 22nd week of pregnancy. The rate of miscarriage was followed across all pregnancies.

Overall, 58 women (3.5%) had a miscarriage. Of these, 25 had an early miscarriage within the first trimester. 33 women had a miscarriage in the second trimester. The average time from conception to miscarriage was 87 days. The risk of early miscarriage was increased 2.5-fold if vitamin D levels were low. However, low Vitamin D levels did not increase the risk of second-trimester miscarriages. No differences in age, body mass index (a measure of body fat that takes weight and height into account) before pregnancy, or number of previous pregnancies were noted between women that miscarried and those that did not.

Researchers concluded that low vitamin D levels during the first trimester are a risk factor for early miscarriages. 

Randomized trials are needed investigating the effect of vitamin D supplements in reducing the risk of early miscarriages. 

Discuss with your doctor whether vitamin D supplements would be helpful. Always discuss any type of supplementation during pregnancy with your doctor before starting.