Episode #146: Supplement Spotlight: How Vitamin D Supports Hormones, Fertility, and Metabolism in PCOS

Welcome back to the PCOS Repair Podcast, where today we’re doing a supplement highlight episode all about vitamin D.

Vitamin D is something we talk about a lot—it’s often called the “sunshine vitamin”—and we know it’s important, but many people don’t really understand why. Most just know we get it from the sun. In today’s episode, we’ll cover why vitamin D is so important for PCOS, how to get it, what happens if you’re not getting enough, and whether you should be paying more attention to your vitamin D levels.

Why Is Vitamin D Important?

Vitamin D is primarily known for supporting bone health. It plays a key role in helping the body absorb calcium from food, which is critical for strong bones, teeth, and other tissues. Without adequate vitamin D, even if you’re getting enough calcium, your body won’t be able to use it effectively—leading to weaker bones and a higher risk of osteoporosis as we age.

Vitamin D also plays important roles in:

• Muscle function (reducing spasms, cramps, or involuntary contractions)
• Inflammation reduction
• Cellular repair and regeneration
• Neuromuscular and immune system regulation
• Glucose metabolism

If you caught those last few—glucose metabolism, inflammation, and cell health—those are buzzwords we hear constantly in relation to PCOS and our metabolic health. So while vitamin D is vital for overall health, it’s especially important for managing PCOS.

How Do We Get Enough Vitamin D?

Let’s talk about how vitamin D is absorbed and where we get it.

First, vitamin D is a fat-soluble vitamin. This means that if you’re taking it orally, you need some dietary fat present to help with absorption. It doesn’t have to be a lot, just a small amount of healthy fat included in the meal or taken with an oil-based vitamin D supplement (like drops in MCT or olive oil) will do the trick.

Dairy products are often fortified with vitamin D and typically contain enough fat to aid in absorption. Even low-fat dairy can be sufficient.

If you’re getting vitamin D from the sun, there are a few important things to know:

• You need consistent exposure to maintain optimal levels.
• A little goes a long way—just a few minutes a day on exposed skin can be enough.
• However, factors like cloud cover, pollution, sunscreen, and clothing can block UVB rays and reduce vitamin D production.
• UV exposure, while helpful for vitamin D, is also the top preventable risk factor for skin cancer. So there’s a balance to be found.

Personally, I live in Oregon where the weather is cloudy and rainy for a good portion of the year. During the summer and early fall, I get decent sun exposure, but for the rest of the year, I rely on supplementation. I’d rather consistently take vitamin D than risk under-supplementing or overexposing myself to UV rays.

Who Might Be at Risk for Deficiency?

Even if you’re outside or eating fortified foods, you might still be low on vitamin D. Here are a few reasons why:

• Certain chronic illnesses (like cystic fibrosis or inflammatory bowel issues) impair absorption.
• People with a BMI over 30 may store vitamin D in fat cells, making it less available for use in the body.
• Your body may struggle with the two-step activation process of vitamin D (involving the liver and kidneys).
• Low-fat diets or poor dietary intake in general can contribute as well.

How to Test for Vitamin D Deficiency

To know if you’re deficient, your doctor can run a blood test called the 25-hydroxy vitamin D test. Results under 20 ng/mL are typically considered deficient, though reference ranges vary slightly by lab. It’s important to compare your results not just to the “normal” range, but to your past results to get a better picture of your trends over time.

If your levels are low:

• Choose a method to improve them (food, supplementation, or lifestyle changes).
• Retest in about three months.
• Once your levels are stable, annual testing is typically enough to monitor your vitamin D status.

It’s also worth noting that your test results may vary depending on the time of year. If you want a more accurate picture, try testing in late winter or early spring—after a stretch of low sun exposure.

If you’re someone who enjoys diving into data, you might even test in both summer and winter to see the difference and plan your supplementation accordingly.

Supplementing with Vitamin D

If you’re going to supplement:

• Choose high-quality brands (I list my favorites in my free PCOS Supplement Guide—linked below).
• Look for third-party tested products, ideally offered through a platform like Fullscript.
• Be cautious with dosing—fat-soluble vitamins can accumulate in the body, so avoid megadoses unless instructed by your healthcare provider.

You can find my supplement guide at supplementsforpcos.com. It includes dosing suggestions, brand recommendations, and guidance to begin a conversation with your healthcare provider.

Final Thoughts

Vitamin D plays a meaningful role in your PCOS journey—but it’s just one piece of the puzzle. No supplement, including vitamin D, is going to “cure” PCOS. That said, it can significantly support your efforts when combined with nutrition, movement, mindset, and a lifestyle that supports hormone balance.

So, is vitamin D going to magically solve your insulin resistance or reverse your PCOS symptoms? No. But if you’re deficient, correcting that deficiency could remove a major roadblock on your path to feeling better.

If you found this episode helpful, head over to supplementsforpcos.com and request the guide. You’ll get access to my full list of recommended supplements, all through a trusted platform with a built-in discount for my listeners.

And don’t forget to hit that subscribe button so you get notified every week when a new episode drops.

Until next time, bye for now.