The days are getting shorter, and darker. It’s time to get your vitamin D levels checked!


Vitamin D is often referenced for its role in bone health, and immune health. However, Vitamin D also has a major role in reproductive health and fertility. It is often missed during a standard fertility workup. Given the prevalence of vitamin D deficiency here, in the pacific northwest, Vitamin D levels should be checked in everyone. 

What is Vitamin D? 

Although it’s classified as a vitamin, Vitamin D behaves more like a hormone. It interacts with numerous areas including our immune system, bone health, reproductive and endocrine system, mental health and so much more. Its claim to fame is its role in calcium metabolism; increasing levels of calcium and thus benefiting bone health. However, its benefit is not limited to this. Low levels of vitamin D have been seen in conditions such as cancer, autoimmune disease, thyroid disorder, depression, anxiety, PCOS, and SO much more.


Vitamin D & Fertility

Unfortunately, there’s not a lot of funding looking at vitamins/minerals and overall health or fertility. However, if we look at the best available evidence, Vitamin D and its role in reproductive health should not be ignored. Here are a few highlights from a systematic review on Vitamin D and fertility:

  1. Vitamin D receptors are found within the ovaries, the pituitary gland, and the endometrium, indicating direct, local action
  2. Has a role in sperm production and maturation
  3. Helps with the production of steroid hormones – including thyroid, progesterone, estrogen, and androgens.
  4. May play a role in uterine receptivity and implantation
  5. Involved in the energy production within sperm – which is thought to help with “capacitation”, or ability to fertilize an egg.
  6. Reduced oxidative stress – a known factor in poor sperm quality and poor egg quality
  7. May play a role in follicle development
Can’t I just take Vitamin D? Why do I need to get tested?

Deficiency is extremely common, especially here in the pacific northwest. On the flip side, you can also have vitamin D toxicity. While this is rare, over-supplementation is the primary cause of vitamin D toxicity. When it comes to fertility and reproductive health (or general health for that matter), we want to see you within the optimal ranges. As with all hormones, it’s all about balance and having the appropriate amount. 


Testing allows up to customize the dose. Many times I’ve seen patients supplement long term and continue to be deficient, and far from the optimal levels. Additionally, if you have been supplementing long term and haven’t seen a shift in your numbers, this may mean you need to change up the route of administration (i.e. switch to Vitamin D shots). Finally, if we’re working on optimizing levels, whether it’s through oral supplementation or injections, monitoring your levels and ensuring safety is important because too little is too little, and too much is too much.


Interested in getting tested or learning more about Vitamin D supplementation or injections – give us a call to set up a free 15 minutes Q&A.


In health,

Dr. Ashley Damm
Naturopathic Doctor- Vancouver, BC

naturopath vancouver