Vitamin D and PCOS; What You Need to Know

Do you know what your vitamin D levels are? If not, you should!  Studies have shown that up to 85% of PCOS patients are deficient in vitamin D. Vitamin D is so potent that it’s also considered a vitamin and protects your bones, brain and heart.  It also plays many important roles in PCOS, including decreasing resistance and inflammation and improving fertility and mood. And with the cold weather, we tend to spend more time indoors and get less of the “sunshine” vitamin. So make sure to get your Vitamin D levels tested and take a supplement if it’s low. Read on to learn more about the benefits of vitamin D for PCOS.

What is Vitamin D?

Vitamin D is a fat soluble vitamin  that helps your body absorb calcium, one of the main building blocks for strong bones. Together with calcium, vitamin D helps protect you from developing osteoporosis, a disease that thins and weakens the bones and makes them more likely to break. Your body needs vitamin D for other functions too. Your muscles need it to move, and your nerves need it to carry messages between your brain and your body. Your immune system needs vitamin D to fight off invading bacteria and viruses.

It’s known as the sunshine vitamin because your body makes it when exposed to sunlight. The ultraviolet rays from the sun strikes your  bare skin (without sunscreen) and promotes vitamin D synthesis and absorption. And for most people, spending just five to 30 minutes outside twice a week is enough for the body to make adequate amounts of vitamin D. You can also obtain smaller amounts from foods, foods fortified with vitamin D as well as supplements.

And while vitamin D deficiency is very common in PCOS, people of color and those with obesity also have very high rates of deficiency. It’s believe that fat cells in obesity decrease the ability to convert vitamin D to its hormonally active form. And people of color have more melanin in their skin which to also decreases the body’s synthesis of  vitamin D from the sun, resulting in lower 25-hydroxyvitamin D levels.

Health benefits of Vitamin D for PCOS

Vitamin D has many health benefits in the body ranging from bone health to brain health. While further research  is needed, studies are suggesting low vitamin D levels may exacerbate the symptoms of PCOS, including insulin resistance, ovulatory, menstrual irregularities, infertility, hyperandrogenism, obesity and elevate the risk of cardiovascular diseases.

• Improved fertility
  Vitamin D may help to regulate the menstrual cycle. A study showed  that taking taking 400 international units (IU) of vitamin D with 1000 milligrams (mg) of calcium for 3 months helps to regulate the menstrual cycles of women with PCOS. Vitamin D has also been shown to aid in the production of normal, mature eggs needed for a healthy pregnancy. Lastly, vitamin D also helped women with PCOS who were taking the fertility drug Clomid (clomiphene). With the vitamin supplements, these women had more success conceiving via in vitro fertilization (IVF).
• Insulin resistance
  Insulin resistance affects 50-95% of people with PCOS, depending on the diagnostic criteria used. Low vitamin D levels may be exacerbating this. A study found that a deficiency of vitamin D had an association with reduced insulin sensitivity and that corrections of this deficiency through  supplementation contributed to improved insulin sensitivity, along with weight loss. A review of randomized controlled trials in women with PCOS showed that supplementing with Vitamin D supplementation restored physiological serum 25(OH)D levels. In six studies, it significantly decreased fasting plasma glucose and brought improvements in insulin resistance and serum fasting insulin.

• Reduced Risk of Metabolic Syndrome
  Metabolic syndrome, also known as insulin resistance syndrome, is a cluster of metabolic disorders that increase the risk of cardiovascular disease, diabetes, and stroke. For example, high blood pressure is a serious medical condition, but when it’s combined with high fasting glucose levels and abdominal obesity, there is a greater chance for cardiovascular problems because of the combination. The metabolic syndrome affects 33% of PCOS patients. You have metabolic syndrome if you have three or more of the following:
  • Abdominal obesity (waist circumference of greater than 35 inches in women)
  • Triglyceride level of 150 milligrams per deciliter of blood (mg/dL) or greater
  • HDL cholesterol of less than 40 mg/dL in men or less than 50 mg/dL in women
  • Systolic blood pressure (top number) of 130 or greater, or diastolic blood pressure (bottom number) of 85 or greater
  • Fasting glucose of 100 mg/dL or greater

  Vitamin D has been shown to improve metabolic syndrome by  lowering triglycerides, insulin and blood sugar.

• Improved mood
  Women with PCOS have been shown to suffer from higher rates of depression and other mood disorders as compared to people without PCOS. While there are many possible reasons for this,  some studies have suggested a correlation between vitamin D deficiency and worsened mood. references. Further research is needed.
• May lower androgens
  This study showed high-doses of vitamin D (4000 IU), compared with low-dose (1000 IU), and placebo, showed beneficial effects on total testosterone, sex hormone-binding globulin (SHBG) and free androgen index (FAI).
  
  

How much Vitamin D you need?

The current recommended daily intake for women is 600 IU, however there isn’t a specific dose recommended for PCOS patients. What’s more important is what your current blood levels are.  Vitamin D known as 25-hydroxyvitamin D is measured in either nanomoles per liter (nmol/L) or nanograms per milliliter (ng/mL) in the blood. One nmol/L is the same as 0.4 ng/mL.

As per the NIH:

• Levels of 50 nmol/L (20 ng/mL) or above are adequate for most people for bone and overall health.
• Levels below 30 nmol/L (12 ng/mL) are too low and might weaken your bones and affect your health.
• Levels above 125 nmol/L (50 ng/mL) are too high and might cause health problems*Note; some experts recommend as high as 80 nmol/L

Food sources of Vitamin D

In the diet, vitamin D can be obtained through food sources including:

• Fatty fish (salmon, tuna, trout)
• Mushrooms
• Eggs
• Milk and yogurt 
• Fortified non-dairy products (almond milk, rice milk)

However, most people are unable to meet their vitamin D needs through food alone and a supplement if usually needed. To learn more about vitamin D, check out the NIH supplement facts sheet. 

Here’s a tip: take your vitamin D supplement with food containing some fat to increase the absorption rate!

Bottom line

It’s important to know what your vitamin D levels are, as it’s one of the most important micronutrients for PCOS.  If you don’t know your levels, ask your doctor to test for it!

Do you know what your Vitamin D levels are?

I’d like to thank Justine Lee for writing this blog post. Justine completed her undergraduate degree in Nutrition and Food Studies from NYU. She is now completing her dietetic internship at the CUNY Graduate School of Public Health. Having worked in the food industry for as long as she can remember, wearing many different hats, Justine now looks forward to moving forward as a Registered Dietitian. Beyond PCOS, her interests in dietetics include food policy, disordered eating, and bariatric nutrition.