Short answer: Vitamin D appears to play a role in fertility. Studies show that women with vitamin D deficiency are less likely to succeed with IVF, and deficiency is common – especially in the Nordic countries during winter. However, it is not yet fully established whether supplementation itself improves outcomes. Among other things, vitamin D contributes to the normal function of the immune system.
Why would vitamin D affect fertility?
Vitamin D receptors are found in several reproductive tissues in both women and men – including the ovaries and uterine lining. This makes it biologically plausible that vitamin D status can affect ovarian function, embryo quality, and uterine receptivity.
What does the research say?
A systematic review and meta-analysis of women undergoing assisted reproduction found that those with vitamin D deficiency had a lower chance of live birth on average than those with sufficient levels. At the same time, it is still unclear whether vitamin D supplementation itself improves IVF outcomes – more and larger studies are needed here. Nevertheless, avoiding deficiency still seems reasonable.
Deficiency is common in the Nordic countries
Since vitamin D is produced in the skin by sunlight, many people in the Nordic countries have low levels during the winter months. Supplementation is often recommended, especially before and during pregnancy.
Frequently Asked Questions
How do I get vitamin D?
Through sun exposure, fatty fish, fortified foods, and supplements. During the winter months, supplements are often warranted.
Can you get too much?
Yes, vitamin D is fat-soluble and stored in the body – do not exceed the recommended dose.
This article is general information and does not constitute medical advice. Consult a doctor or midwife about dosage.
Sources
- Chu J, et al. (2018). Vitamin D and assisted reproductive treatment outcome: a systematic review and meta-analysis. Human Reproduction.