Ladies if you’re considering in vitro fertilisation (IVF), you may want to check your vitamin D status prior to the treatment. A new study published in CMAJ Open suggests that women who have optimal levels of the ‘sunshine vitamin’ are more likely to undergo successful IVF compared to those with inadequate levels.

Why we need vitamin D

In a nut-shell, vitamin D helps maintain strong bones and teeth by ensuring calcium and phosphorus balance. This vitamin also regulates cell growth as well as nerve, muscle and immune function. And it is also active in reducing inflammation and may even have cancer-protective properties.

Study details

The researchers selected 173 women undergoing IVF at Mount Sinai Hospital in Toronto, Ontario. The vitamin D status of these women was evaluated by analysing the levels of 25-hydroxy vitamin D in blood samples: levels lower than 75nmol/L were considered to be insufficient.

Study findings

54.9% of the study participants had low levels of 25-hydroxy vitamin D. The scientists noted that the remaining 45.1% who had adequate levels of the vitamin had significantly higher rates of clinical pregnancy per IVF cycle started (52.5%) compared with women with insufficient levels (34.7%).

It also appeared that women who were overweight were more vulnerable to vitamin D deficiency — a finding which has been reported in previous studies. Scientists hypothesise that since vitamin D is a fat soluble vitamin, adipose (fat) tissue stores this vitamin, making it less bioavailable.

Vitamin D deficiency and pregnancy: results of other studies:

  • Higher risks of gestational diabetes. Researchers found that women who were vitamin D deficient during their first trimester were more likely to develop diabetes later during their pregnancy.
  • Foetus predisposed to multiple sclerosis (MS). Inadequate vitamin D levels may adversely affect the immune system of the developing baby, making her/him more vulnerable to MS, a condition where the immune system attacks the nerves.
  • Baby at risks of rickets: The baby would be at higher risk of fractures and bone malformations and may be sicklier from birth through adulthood.

What this means for you

  • Keep your vitamin D status in check — your GP can refer you for a blood test.
  • If you’ve got excess body fat, contact a dietitian to help you get rid of the extra kilos before you undergo IVF.

Where can you get vitamin D?

The best source is sunlight: our body is able to synthesise the vitamin when exposed to sunlight. This gives you a perfect reason to bask in those warm early morning rays for about 15 minutes a day with minimal clothing and no sunscreen. Remember you don’t need to get tanned: your body does not need that much sunlight to produce enough vitamin D.

Food sources of vitamin D include oily fish such as salmon, mackerel, tuna and sardines; whole eggs and vitamin D fortified milk.

What if you’re vegetarian or vegan? You can get vitamin D in Portobello mushrooms, bran flakes and vitamin D fortified cereals.

Do you need a vitamin D supplement?

The NHS advises pregnant and breastfeeding women to take a daily supplement of 10 micrograms of vitamin D. To be on the safe side, talk with your GP about the need for a vitamin D pill.


    Garbedian K et al (2013) Effect of vitamin D status on clinical pregnancy rates following in vitro fertilization. CMAJO. 1:E77-E82;