If you’re thinking about having a baby it’s strongly recommended that you have your Vitamin D level checked, especially if you’ve been trying for a while or have a history of pregnancy loss. Your doctor can order a simple blood test to ensure you have enough of this vitamin that is so important for fertility and healthy pregnancies – for both mothers and their children. Vitamin D is typically low in the winter and spring months and in darker northern climates. A Vitamin D deficiency puts pregnant women at risk of developing serious health complications.
Preconception & Infertility
If you’re having trouble conceiving, low Vitamin D could be contributing to your fertility issues. A low level has been associated with Repeated Pregnancy Loss and Unexplained Infertility. It’s been found to affect implantation which can cause bio-chemical pregnancies or miscarriages. [i]. Also more research is being done on PCOS (Polycystic Ovarian Syndrome) since these women often have Vitamin D deficiency and evidence is showing that supplementation may be beneficial for egg development and regulating menstruation. [iii]. One study found a healthier increased uterine lining in women with PCOS who were given Vitamin D during their IUI cycles. [ii].
A study (published in Fertility & Sterility in 2014) of 99 women undergoing IVF (in-vitro fertilization) at USC in Southern California looked at the impact of Vitamin D on IVF cycles. The percentage of women who became pregnant was 74% in those with sufficient vitamin D levels (above 30 ng/ml), 42% in women who were insufficient (20-30), and only 35% with deficiency (below 20). Babies were born to 59% of the women with adequate D levels (above 30) and 31% of women whose levels were below 30. [iv].
Vitamin D in Pregnancy
Vitamin D is very important for brain development. A recent study in the Netherlands of more than 8,000 women and their children showed a clear correlation between Vitamin D deficiency and autism. Children whose mothers tested low in their 20th week of pregnancy were more likely to have autistic traits by the age of six. [v]. Other studies have seen an increased risk of schizophrenia with inadequate Vitamin D. [vi, vii].
When mom’s Vitamin D level is too low deficiency can be present at birth. Babies receive this vitamin through the placenta, and after birth through breast milk or fortified formula. Babies who are solely breastfed are more at risk of having deficient Vitamin D because human milk has a very low concentration, about 1.5-3% of the mother’s level. So, exposure to sunlight is also recommended. [viii]. An Irish study found their dark winters produced more babies born in March and April with Vitamin D insufficiency, about 46% of births during that time. You can read more about the importance of Vitamin D during pregnancy and while breastfeeding here.
Low Vitamin D during pregnancy has been linked to small-for-gestational-age births, increased susceptibility to infections and reduced bone density. [viii]. Kids whose moms did not have sufficient Vitamin D in their 3rd trimester had more broken bones than other children. An Australian study published in 2016 tells us that children who have a lack of D in early childhood are more prone to developing allergic disorders like asthma and eczema. [ix].
Also, it’s very important to know that pregnant women with low D are more susceptible to developing preeclampsia, a complication of pregnancy including high blood pressure and kidney problems which can have very serious consequences. [x]. Often an earlier birth by medical induction is necessary, which increases the odds of a cesarean delivery. Vitamin D deficiency has also been associated with developing gestational diabetes, so, you definitely want to make sure your level stays within optimum range. Continue reading