Real talk: I was planning to do a comprehensive guide of the best PCOS supplements. But, it’s a lot of work digging through all the research, and I wanted to get at least some of the info out to you. So, here is part one: Nutrients for PCOS!

Polycystic Ovary Syndrome (PCOS) is associated with a range of nutrient deficiencies. Even if you are eating a whole-foods based diet that contains ample vegetables, fruits, and proteins, it is still possible to become deficient in certain nutrients due to the disease process.

In this article, we’ll take a look at the most common nutrient deficiencies, current research in PCOS, food sources of these nutrients, and supplementation recommendations. I will address herbal supplements and other nutrients for use in PCOS in upcoming articles, so stay tuned!

1. Magnesium

Magnesium is a mineral that is abundant in the human body and found naturally in many foods. It plays a key role in over 600 enzyme reactions that affect muscle and nerve function, metabolism, blood sugar levels, and blood pressure (1, 2).

Magnesium deficiency is common in women with PCOS. Additionally, if you have ever taken birth control pills, they reduce levels of this important nutrient as well. Magnesium supplements have been shown to improve insulin resistance, decrease the risk for developing diabetes, and improve inflammation (3, 4, 5).  All reasons why this is an important nutrient to take if you have PCOS.

Foods High in Magnesium (6):

• Seeds (pumpkin seeds, sunflower seeds, sesame seeds)

• Nuts (almonds, hazelnuts)

• Legumes (peanuts, black beans, soybeans)

• Whey protein

• Grains (rice, oats, sorghum, barley, teff)

• Vegetables (spinach, potatoes)

• Raw cacao (my favorite source of magnesium!)

Dose: 400 mg of magnesium in the form of magnesium chelate or magnesium glycinate. You should not take magnesium citrate unless you have constipation, as it may cause loose stools. Additionally, magnesium, when taken long-term, should be used in combination with calcium in a 2:1 ratio of calcium to magnesium (so, if you take 400 mg of magnesium, you would take 800 mg of calcium). Pure Encapsulations makes one in this ratio.

2. Vitamin D

Vitamin D plays important roles in reproductive hormone regulation and impacts anti-mullerian hormone (AMH), follicle stimulating hormone (FSH), and progesterone levels. It also is necessary for blood sugar balance and insulin regulation (7).

67–85% of women with PCOS are deficient in Vitamin D (8). Your risk increases if you live in a part of the world where you don’t get much sunlight.

Studies have shown that vitamin D supplementation improves fertility, decreases testosterone levels, and lowers inflammation (as measured by hs-CRP levels) in women with PCOS (9, 10, 11).

Foods High in Vitamin D (12):  

• Fortified dairy products

• Eggs

• Liver

• Fish (swordfish, salmon, tuna)

• Cod liver oil

Dose: The optimal dose of vitamin D is not known. The current recommendation is 600 IU/day; however, many experts agree this level is too low. You should have your vitamin D levels checked by a healthcare practitioner. Optimal levels of 25(OH)D are ≥50 nmol/L. High doses of vitamin D (up to 10,000 IU/day) may be necessary to replete your levels if you are very deficient, and then optimal levels can usually be maintained with a dose of 1000–2000 IU/day. It is important to take vitamin K along with vitamin D to reduce the risk of calcium deposits in your arteries. I like Thorne vitamin D/K2 drops.

3. Zinc

Zinc is a trace nutrient involved in hundreds of enzyme reactions in the body. It is necessary for regulating the menstrual cycle and fertility. Women with PCOS may be deficient in this essential metal. Additionally, birth control pills deplete zinc levels.

Studies have shown that zinc supplementation in women with PCOS improves fertility and reduces the effects of high testosterone, including acne, hirsutism, and hair loss (13, 14).  Zinc, in combination with magnesium, has also been shown to reduce inflammation in women with PCOS (15).

Foods High in Zinc (16):

• Shellfish (oysters)

• Meat (beef, bison, lamb, turkey)

• Legumes (black beans, azuki beans)

• Seeds (pumpkin seeds, sunflower seeds)

• Whey protein

Dose: The RDI of zinc for women is 8 mg/day. Long-term use of zinc may affect iron and copper levels in your body, so be sure to work with a healthcare professional to determine if this is a nutrient that is appropriate for you. Zinc picolinate is an easily absorbable form of this nutrient.

4. Vitamin B12

Vitamin B12 is required for red blood cell formation, DNA synthesis, and nerve function. This vitamin is found primarily in animal foods, so the risk for deficiency is higher in vegetarians and vegans. Women with PCOS and insulin resistance have been found to have lower B12 levels than women with PCOS without insulin resistance, and women with PCOS who were obese had lower B12 levels compared with women who were obese but did not have PCOS (17). Additionally, studies have shown that metformin use significantly lowers serum B12 levels (18, 19). Vitamin B12 supplementation may improve fertility and fatigue in women with PCOS.

Foods High in Vitamin B12 (20):

• Shellfish (mussels, oysters, crab)

• Fish (herring, salmon)

• Meat (liver, beef, pork)

• Eggs

• Dairy products

Dose: The RDI of vitamin B12 for women is 2.4 mcg/day. Methylated B12 (methylcobalamin) may be easier to absorb than cyanocobalamin, and may be necessary if you have a MTHFR mutation (more on this in a future article). Methylated B12 may increase anxiety levels, so work with your healthcare practitioner to determine if the adenosylcobalamin or hydroxycobalamin forms of B12 might work better for you.  B12 should generally be taken in combination with other B vitamins, so that imbalances do not develop.

5. Folate

First, let’s clear up some confusion about folate/folic acid. Folate is the form of vitamin B9 that is found in foods, such as leafy greens. Folic acid is the synthetic form of the vitamin (made in a lab).

Why does that matter? People with certain variations (mutations) of the MTHFR (methylenetetrahydrofolate reductase—say that 10 times fast) gene SNP (single nucleotide polymorphism—another mouthful) cannot make the enzyme needed to convert folic acid to 5-methyltetrahydrofolate, the active form (21). Up to 50% of people have at least one variant in the MTHFR gene. Even one variant is associated with decreased ability to convert folic acid to folate.

So, if you have a MTHFR mutation, it is very important that you take methylfolate (or L-5-methyltetrahydrofolate) and avoid the synthetic folic acid (found in vitamins and supplemented foods). I will do a deep-dive into the implications of MTHFR in a future article. If you are trying to get pregnant, I always recommend being tested for MTHFR so that you know your status.

Studies have shown that 5 grams of folate improved blood sugar control and lipid levels and lowered inflammatory markers in women with PCOS (22, 23).

Foods High in Folate (24):

• Legumes (azuki beans, black beans, soybeans)

• Vegetables (asparagus, beets, spinach, broccoli, peas, cabbage, collard greens)

• Fruits (mangoes, oranges)

Dose: The RDI of folate for women is 400 mcg/day or 600 mcg/day if you are pregnant or trying to get pregnant. Higher doses may be necessary if you have a MTHFR mutation. Thorne makes a nice combination product that contains L-5-MTHF as well as active B12.

Other Nutrient Deficiencies Caused by Common PCOS Medications

Many medications commonly prescribed for PCOS can lead to nutrient deficiencies. So, if you’re taking any of the below medications, be sure to be tested for these deficiencies and work with your healthcare practitioner to determine a plan to get you back to optimal levels.

• Birth control pills: folate, magnesium, zinc, vitamin B12, vitamin A

• Metformin: vitamin B12, vitamin B1 (thiamine), folate

• Spironolactone: folate, sodium

• Additionally, many SSRI antidepressants also deplete folate

Sign up for our free masterclass – PCOS Period Success: 3 Simple Diet Shifts You Can Make NOW to Get Your Period Back now to learn more!

Stay tuned for the next article in this series, where I’ll discuss herbal supplements and other nutrients beneficial for PCOS.

IMPORTANT NOTE -> This information is provided for educational purposes and should not be construed as medical advice. Please consult with your healthcare practitioners before undertaking any changes in your diet or adding supplements.