Vitamin D for PCOS: The Key to A Healthy Pregnancy

New guidelines have come out about the importance of vitamin D for PCOS, especially as it’s the key to a healthy pregnancy. Here’s what you need to know.

Vitamin D is not just a vitamin, but also a hormone. As a hormone, vitamin D receptors have been found to be at every cell, including the cells of the uterus, ovaries and follicles. Adequate vitamin D is linked to better fertility in women with PCOS. Women with PCOS who were deficient in vitamin D were shown to have more problems getting pregnant.

New research has now looked at vitamin D for PCOS during pregnancy and found adequate vitamin D holds the key to a healthy pregnancy. This is important for folks with PCOS as most people are deficient in vitamin D. Pregnancy increases the demands of vitamin D, increasing the risk of deficiency and leading to complications.

Here are some of the important roles vitamin D plays in pregnancy for PCOS.

PCOS to pregnant course

Vitamin D Improves Ovulation for PCOS

Vitamin D plays a significant role in ovulation in PCOS. One study found vitamin D levels were an independent predictor of successful ovulation following ovulation induction. According to the results of a randomized trial, the  probability of ovulation correlates with vitamin D levels in PCOS, showing 68% probability below levels of 20 ng/mL, 77% between 20–30 ng/mL, and 78% above 30 ng/mL.

Vitamin D Improves IVF Outcomes for PCOS

Vitamin D levels influence the outcomes of in vitro fertilization (IVF), independently from age, body mass index (BMI), ethnicity and the number of embryo transfers. Vitamin D levels are correlated with success rates: one study shows every nmol/L increase in the vitamin D content of the follicular fluid increases the probability of pregnancy by 2.4%.

It was found that both implantation and occurrence of pregnancy were significantly higher in patients with normal vitamin D levels compared to those with decreased levels of vitamin D (<20 ng/mL 25(OH)-vitamin D). Vitamin D has also been shown to improve embryo quality.

Vitamin D for PCOS and Healthy Pregnancy

Vitamin D needs increase in pregnancy, yet as many as 70% of women have been found to be deficient. This is concerning as numerous complications during pregnancy have been linked to low vitamin D levels. These complications include gestational diabetes, preeclampsia, premature birth and miscarriage.

One study found the risk of premature birth decreases by 60% when vitamin D levels are above 40 ng/mL.

Maternal vitamin D supplementation has been shown to reduce the risk of low birth weight and small-for-gestational-age (SGA) births.

pcos ultra D

Vitamin D with k2 for maximum absorption


Vitamin D Prevents Miscarriage

Research shows a relationship between low vitamin D and increased miscarriage rates. In a large review, Vitamin D levels below 50 nmol/L were associated with an increased risk of miscarriages.

Vitamin D Deficiency in Pregnancy and Health Risks in Children

Children born from mothers with low vitamin D levels are linked to increased health risks during childhood and later in life. These health risks include autism, asthma, schizophrenia, diabetes and insulin resistance. The risk of Type 2 diabetes increases 2-fold in children born under vitamin D-deficient conditions.


How Much Vitamin D Is Needed in a PCOS Pregnancy?

Vitamin D needs are higher in pregnancy. It has been suggested that vitamin D levels be a minimum of 30 ng/mL or 75 nmol/d during pregnancy. For pregnant women with PCOS, 2,000–4,000 IU daily doses of vitamin D supplementation are recommended. Since vitamin D is fat soluble, it will absorb best if its taken with a meal that contains fat.

Women who are planning pregnancy, vitamin D supplementation should start earlier to ensure optimal vitamin D levels (30–50 ng/mL or 75–125 nmol/L 25(OH)-vitamin D), to support a healthy pregnancy, and to help with conception.


Várbíró S, Takács I, Tűű L, Nas K, Sziva RE, Hetthéssy JR, Török M. Effects of Vitamin D on Fertility, Pregnancy and Polycystic Ovary Syndrome-A Review. Nutrients. 2022 Apr 15;14(8):1649.

Leave A Comment

Your email address will not be published. Required fields are marked *

No Comments

No comments yet.

Sign Up!

pcos supplements