Everything You Need to Know About Vitamin D for Your Health

• Vitamin D3 is important for bone strength and immune function; your body produces it naturally from sunlight or you can get it through supplements when sun exposure is limited
• The optimal blood level of vitamin D is between 60 and 80 ng/mL; to stay in this range, test your levels regularly and adjust sun exposure or supplementation accordingly
• Getting safe sun exposure requires monitoring your skin for even a slight shade of pink, while avoiding peak hours until you’ve reduced seed oil consumption for six months
• Risk factors for vitamin D deficiency include darker skin, older age, living in northern climates, limited outdoor time, obesity and certain digestive conditions
• Beyond bone health, optimal vitamin D levels help reduce your risk of chronic diseases, autoimmune conditions and mood disorders, while improving COVID-19 outcomes

You’ve probably heard about vitamin D from your doctor or a friend — and how your body produces it when you spend time outside on a sunny day. But why does vitamin D matter so much for your health? In the video above, Dr. Sunil Wimalawansa breaks it all down for you in a simple way, explaining the essentials of why you need vitamin D to keep your body feeling great.¹

Vitamin D is like a superhero for your body. It’s a nutrient that helps your bones stay strong, your immune system fight off germs and even boosts your mood. You probably think of it as something you get from the sun — and you’re right. Because sun exposure has many health benefits beyond vitamin D, it’s useful to view your vitamin D level as a marker showing you’re getting the right amount of sun exposure. But there’s more to the story.

What Is Vitamin D and Why Should You Care?

There are a few types of vitamin D, but the one you really need to know about is vitamin D3 (cholecalciferol). Your skin makes vitamin D3 when sunlight hits it, and it’s found in supplement form. There’s also vitamin D2 (ergocalciferol), which comes from plants, including yeast and mushrooms exposed to ultraviolet (UV) light, making it a popular option for vegetarians and vegans.

However, vitamin D3 is significantly more effective than D2 at raising blood vitamin D levels. Another form, called calcifediol, is a vitamin D3 analog used in special medical cases, but for everyday life, stick with D3. The active version your body uses is calcitriol, which helps control things like calcium levels and regulates gene expression, influencing many cellular processes, including cell growth and differentiation, immune function and inflammation.

Why should you care? Because without enough vitamin D, your body can’t work at its best. It’s key for strong bones, fighting colds and even lowering your risk of serious diseases.

How Does Vitamin D Work in Your Body?

Your body uses vitamin D in two primary ways, and both are important for your health.

1. Keeping your bones strong — This is the job of your endocrine system. When you have enough vitamin D, it turns into calcitriol in your kidneys. This helps your gut pull calcium from food to build strong bones. Without it, children get rickets (soft bones) and adults develop osteomalacia, or weak, painful bones. Vitamin D gives your skeleton the tools it needs to stay tough.
2. Boosting your immune system and more — Other cells — like your immune cells — use vitamin D differently. These are called peripheral target cells. They need vitamin D3 directly to make calcitriol inside themselves. This powers up your immune system to fight off viruses, keeps your heart healthy and even helps your brain stay sharp.

Here’s the catch: these two systems need enough vitamin D3 to do their jobs. If you’re low, your bones might weaken and you could get sick more often. So, how do you make sure you’re getting enough?

What’s the Best Way to Get Vitamin D?

You’ve got two main options to keep your vitamin D levels up: sunlight and supplements. Sunlight is the best option for optimizing your vitamin D levels. Let’s break it down.

• Sunlight is nature’s vitamin D factory — When sunlight hits your skin, it turns a substance in your body into vitamin D3. Here’s how to get sun exposure safely:
  • How much sun? Expose your bare skin to direct sunlight daily. To gauge safe sun exposure, perform a simple “sunburn test.” Pay close attention to your skin as you’re in the sun. You’re aiming to stay just below the point where your skin starts to turn even slightly pink. Any redness at all is a signal to get out of the direct sun, so avoid getting a sunburn — that’s a sign of damage, not benefit.
  • Eliminate seed oils before peak-hour sun exposure — Seed oils, rampant in processed and fast food, are packed with linoleic acid (LA). When LA accumulated in your skin interacts with the sun’s UV rays, it triggers inflammation and DNA damage. It’s best to avoid direct sunlight during peak hours (10 a.m. to 4 p.m.) until you’ve cut back on seed oils for six months. This gives your body time to clear some of the accumulated LA.
  • Fun fact — Your body stops making vitamin D when you’ve got enough, so you can’t overdo it from sunlight alone. However, if you have darker skin, you’ll need to spend a more time in the sun to produce the same amount of vitamin D as someone with lighter skin.

However, sunlight isn’t always reliable. If you live far north (like in Canada or Scandinavia), it’s difficult to get enough sun exposure during the winter months. Even in the summer, many people spend most of their time indoors, missing out on valuable sun exposure. That’s where supplements come in.

• Vitamin D3 supplements are a backup plan — Vitamin D3 supplements are inexpensive and easy to find. If you can’t get enough vitamin D from sun exposure, here’s what you need to know about vitamin D supplementation:
  • How much vitamin D3? Your goal is to reach and maintain optimal vitamin D levels, ideally between 60 and 80 ng/mL (150 to 200 nmol/L). The best way to know if you’re in this range is to get your vitamin D levels tested. I recommend doing this twice a year. Based on your test results, adjust your sun exposure or your supplement dose. Regular monitoring is key to keeping your vitamin D level in that sweet spot.
  • Vitamin D3 supplement tip — Take vitamin D3 with a meal that has some healthy fat, like grass fed butter or tallow, to help your body absorb it.

Are You at Risk for Low Vitamin D?

So, sun or supplements — or both — keep your vitamin D on track. But how do you know if you’re low? Some people have a tougher time getting enough vitamin D. You might be at risk of vitamin D deficiency if:

• You have darker skin — More melanin means you need more sun to make vitamin D.
• You’re older — As you age, your skin doesn’t produce it as well.
• You live far north — Weak winter sun makes it challenging to get enough vitamin D from sunlight, especially in the winter.
• You cover up or stay indoors — Clothes and sunscreen block sunlight, so you miss out on vitamin D. Likewise if you don’t spend much time outdoors.
• You have certain conditions — Obesity and gut issues make it harder to use vitamin D.

What Are the Benefits of Optimal Vitamin D Levels?

Keeping your vitamin D level in the optimal range does wonders for your health. Here’s what you gain:

1. Stronger bones — Say goodbye to weak bones. Vitamin D helps prevent rickets in children, osteomalacia in adults and osteoporosis as you get older.
2. Better Immunity — Ever notice you get fewer colds when you’re out in the sun? Vitamin D helps your immune system fight viruses like the flu or even COVID-19.
3. Lower chronic disease risk — Studies link optimal vitamin D levels to less heart disease, diabetes and cancer.² It’s like a shield for your body, helping to ward off chronic disease.
4. Fewer autoimmune problems — Conditions like multiple sclerosis, psoriasis and rheumatoid arthritis are also less likely when you have enough vitamin D.³
5. Happier mood — Feeling down? Some research says vitamin D helps lift your spirits and ease anxiety and depression.⁴

To get these perks, you need steady levels — not just a random dose here and there. Aim for 60 and 80 ng/mL of vitamin D in your blood, and stick with it year-round.

Can Vitamin D Help with COVID-19?

You might’ve heard buzz about vitamin D during the pandemic. In fact, people with low vitamin D levels were more likely to get really sick from COVID-19.⁵ It’s not a magic cure, but having enough vitamin D gives your immune system a boost to fight of viral illness. Some hospitals even use high doses to help patients recover faster. The trick? Keep your levels up before you get sick to build your body’s defenses ahead of time.

There you have it — everything you need to take control of your vitamin D levels and elevate your overall health. From understanding its role in strong bones, a robust immune system and a brighter mood, to knowing how to harness sunlight, supplements and regular testing, you’re now equipped to make a real difference. Your healthier, happier self is just a sunny day away.

FAQs About Vitamin D

Q: What’s the best way to get vitamin D?

A: The best way to optimize your vitamin D level is through sensible sun exposure. However, avoid direct sunlight during peak hours (10 a.m. to 4 p.m.) until you’ve cut back on consuming seed oils for six months.

Unfortunately, getting regular sun exposure is difficult for many, especially during the winter season and/or if you live in northern regions. If you cannot obtain sufficient amounts of vitamin D through sun exposure, taking a vitamin D3 supplement is recommended.

Q: How much vitamin D should I take daily?

A: The only way to know how much vitamin D to take in supplement form is to monitor your levels Test your vitamin D levels twice yearly, adjust sun exposure or supplementation based on the results and retest after three to four months to confirm you’ve reached your target — ideally between 60 and 80 ng/mL (150 to 200 nmol/L).

Q: Can I get too much vitamin D?

A: It’s rare, but very high doses of vitamin D from supplements over time can cause issues like high calcium. However, your body stops making vitamin D when you’ve got enough, so you can’t get too much from sunlight exposure.

Q: What if my vitamin D levels are low?

A: You might feel tired, achy or get sick a lot if you’re vitamin D deficient. Get a blood test to confirm your level, then boost it using safe sun exposure and/or vitamin D3 supplements.

Q: Is vitamin D important for children?

A: Yes, it helps their bones grow strong and keeps their immune system optimized. Children should ideally optimize their vitamin D levels by spending time outdoors in the sun.

• ¹ YouTube, VitaminDAction, Key Fundamental Aspects of Vitamin D, September 24, 2024
• ² J Steroid Biochem Mol Biol. 2023 Jul:231:106308
• ³ Biomolecules. 2023 Apr 21;13(4):709
• ⁴ Nutrients. 2023 Apr 4;15(7):1765
• ⁵ Nutrients. 2022 Apr 13;14(8):1625