Vitamin D: the Neglected Investigation for Fertility
Updated: Feb 10
The role of Vitamin D on reproductive function has been explored over the last couple of decades. The summary of these results paints us a clearer picture on how important this Vitamin is for male and female fertility. Especially living in Canada, where Vitamin D deficiency is present in a large portion of the population, neglecting Vitamin D investigation and appropriate treatment can have significant negative impacts on reproductive outcomes.
For Males the research has very clearly shown that a deficiency in Vitamin D significantly impairs sperm motility. The neck of mature sperm cells have receptors for Vitamin D, and when Vitamin D attaches to that receptor it appears to affect the concentration of calcium inside the spermatozoa. This alteration in calcium concentration appears to significantly affect the progressive motility of sperm cells.
How many Canadians are Vitamin D deficient?
It is estimated that anywhere between 15-75% of females, deepening on ethnicity, may be deficient in Vitamin D levels during the winter months.
How Does Vitamin D affect Female Fertility?
Vitamin D will decrease the receptors for Anti-Mullerian Hormone (AMH) on the follicles/eggs of the ovary. This reduces the stimulation of AMH-2 and AMH-1 receptors, whose specific role is to slow down and prevent follicles from maturing in to healthy eggs. Supplementing with Vitamin D appears to reduce the production of AMH-2 receptors by almost half on the follicles.
Limited research shows that Vitamin D deficiency may induce early menopause
Vitamin D improves the function of enzymes which convert cholesterol to hormones. It has been shown to improve the production of estrogen and progesterone from the ovaries
For Women with polycystic ovarian syndrome (PCOS) supplementing with Vitamin D appears to improve the body's sensitivity to insulin and reduce insulin resistance, it reduces markers of inflammation (high-sensitivity-CRP), it improves natural ovulation rates, and it reduces the production of advanced glycation end products (AGEs) which are harmful when they accumulate in the theca or granulosa cells in the ovary
For Women with Endometriosis: Vitamin D suppressed the production of inflammatory chemicals and is inversely associated with with likelihood of developing endometriosis (the higher the Vitamin D concentration predicted a lower risk for endometriosis)
For Uterine Fibroids: Vitamin D suppresses the production of these benign tumor cells. It is estimated to reduce tumor cell growth by 12%, in fact Women with Vitamin D deficiency were estimated to be almost 2.4 times more likely of developing fibroids
Painful periods (dysmenorrhea): Vitamin D reduces the production of inflammatory cytokines. In a study it was observed that Women who supplemented with Vitamin D did not need analgesic medications while the control group that didn't supplement with Vitamin D had a 40% analgesic use rate
Assisted reproductive technologies (IVF, IUI, ICSI): Vitamin D increases the likelihood of a successful pregnancy. It does this by potentially improving embryo quality as well as improving the thickness of the uterine lining. It is observed that Women with Vitamin D deficiency may have endometrial thickness from reaching the optimal levels
This article is in no way a replacement for medical advice or medical care, it is advised that anyone concerned about their Health should speak with their Naturopathic Doctor.