Vitamin D Facts: Surprising Things You May Not Know About Vitamin D

As with most things on the internet, sorting through vitamin d facts and myths can be confusing. Can we get enough of this vital vitamin from the sun or not? And if so, why are so many people still not getting enough vitamin D? What about food sources of vitamin D? Can a vitamin D supplement or personalized vitamins help? How much vitamin D is too much?

Whether you’re looking to increase your vitamin D intake or just wondering if it’s even worth trying to do so—here are a few interesting facts about vitamin D to help set the record straight.

WE HAVE VITAMIN D RECEPTORS ON ALMOST ALL OF OUR CELLS¹

What do brain cells, immune cells, bone cells, and muscle cells have in common with almost every cell in the body? They all have vitamin D receptors!

Vitamin D is a fat soluble vitamin that plays a vital part in supporting bone health, muscles, and the immune system.^† Getting enough vitamin D is crucial to triggering the vitamin D receptors found in every one of our cells, so they can carry out some of the most important processes in the body.

Nothing else gets these receptors moving into action—just vitamin D. Not getting enough vitamin D can have profound effects throughout the body which is concerning given most of us are not getting enough of this vital nutrient.

MOST PEOPLE DON’T GET ENOUGH VITAMIN D

Vitamin D deficiencies or insufficiencies are a real issue for a lot of people. If you don’t get outside every few days, or if when you do get outside it’s cloudy, polluted, or you’re safely covered up with sunscreen or clothing—you may not be getting enough vitamin D.

More than 40% of the U.S. population has low vitamin D blood levels.² There are portions of the population, such as women, who are at even greater risk of low vitamin D levels.

WOMEN ESPECIALLY ARE LACKING VITAMIN D

A recent study found that over 70% of women ages 15–65 have a vitamin D deficiency or low vitamin D levels.³ That’s a lot of women who are missing out on this crucial muscle, immune, and bone health support nutrient.^†

VITAMIN D IS FOUND ONLY IN A FEW FOODS

Foods are naturally low in vitamin D. The data shows that 95% of Americans are falling short of meeting their vitamin D needs through their diet.⁴

What’s the best source of vitamin D? The foods highest in vitamin D are oily fish or fatty fish. There are also a few vitamin D fortified foods such as orange juice and cow’s milk. You can always check the vitamin D nutrition facts on your food nutrition facts panel to see how much vitamin D it provides.

Here are some food sources of vitamin D:

• Pink salmon
• Mackerel
• Sardines
• Fortified Milk, low-fat cow’s milk, 1% fortified with vitamin D
• Orange juice, fortified with vitamin D
• Fortified cereal
• Egg yolk

THE SUN IS THE BEST SOURCE OF VITAMIN D

There’s a reason vitamin D is called the sunshine vitamin. The best source of vitamin D comes from the sun. But you don’t need sunlight exposure every day to get enough vitamin D. In the right conditions, just 15–20 minutes every few days of sunscreen-free sunlight exposure can provide almost all the vitamin D you need. However, it’s not always easy to do!

SUNSCREEN BLOCKS HOW YOUR BODY MAKES VITAMIN D

Lathering up with sunscreen is vital to protecting your skin from the sun’s powerful rays. That said, sun protection like sunscreen actually blocks vitamin D synthesis (aka how your body makes vitamin D). Even sunscreen as light as 10 SPF can block UVB radiation by as much as 90%.¹

POLLUTION AND CLOTHING CAN BLOCK VITAMIN D TOO

You may already know that clouds can block how much vitamin D your body makes, but air pollution and clothing have a similar effect. Both air pollution and clothing block UVB rays from getting into your skin, which in turn blocks your body’s ability to synthesize vitamin D.

VITAMIN D IS VITAL FOR CALCIUM ABSORPTION TOO

Vitamin D is necessary for your body to absorb calcium, another crucial bone health support nutrient, but here women are missing out too.^† A recent study found that women of all ages weren’t consuming enough calcium from their diet alone.³ To up your daily calcium intake and to further support your healthy bones, consider taking a calcium supplement.

LOW MAGNESIUM INTAKE MAY IMPACT VITAMIN D STATUS

Magnesium is an essential mineral known for its ability to help support nerve, muscle, and heart function.^† But not many people know magnesium is required for vitamin D metabolism too.¹ 

Vitamin D needs to go through several steps in the body (aka metabolism) to turn this nutrient into an “active” form the body can use—and here magnesium plays an important role. So even if you get enough vitamin D from food, supplements, or sunshine—if you don’t have enough magnesium, your body can’t metabolize vitamin D as well.

Over 50% of the population is not meeting their magnesium needs, so addressing magnesium shortfalls is a crucial part of addressing your vitamin D needs too.⁴   

VITAMIN D2 AND VITAMIN D3 ARE DIFFERENT

Vitamin D actually comes in two forms: vitamin D2 and vitamin D3. Although foods are not naturally high in vitamin D, we can find both forms of this nutrient in our diet.

Vitamin D2 is found in plants that are exposed to UVB rays, such as mushrooms or yeasts. Vitamin D3 is made when the skin of animals is exposed to UVB rays, and as such can be found in —humans make vitamin D3 this way, too!¹ Fortified foods and dietary supplements can contain either vitamin D2 or vitamin D3.

VITAMIN D SUPPLEMENTS CAN HELP

A dietary supplement can help fill any gaps that may come from your diet or not spending enough time in the sunshine. If you’re looking for a vitamin D supplement, here are few helpful tips to keep in mind:

• Vie For Vitamin D3: While supplements can contain either vitamin D2 or vitamin D3—vitamin D3 is more effective at raising and maintaining vitamin D blood levels than vitamin D2.¹
• Keep An Eye On Quality: Be sure your supplements have been vetted by third-party organizations for quality, purity, and potency. If this information isn’t immediately available on the label, you should be able to find it online on their website.
• Don’t Forget The Dose: Check the vitamin D nutrition facts on your supplement facts panel for the dosage. Experts recommend 1500–2000 IU of vitamin D daily.⁵ Look for a multivitamin that provides 1000 IU vitamin D, or a vitamin D supplement with 1000–2000 IU.

All that said, depending on your needs or circumstances (sun exposure, where you live, age, weight, skin color, etc.) your vitamin D level requirements may vary. So it’s always a good idea to check with your healthcare practitioner to make sure you’re getting the right dosage and vitamin D supplementation is right for you.

WHATEVER YOU DO, DIG DEEPER FOR VITAMIN D

There’s no doubt that vitamin D is crucial for our bone, immune, and muscle health support.^†  We also know that too many of us aren’t getting enough of it. Whether that’s because we’re covering up outside with sunscreen or shirts, or live in cloudy or air polluted areas. We also aren’t getting enough magnesium, which is essential to helping our bodies use vitamin D.

Whatever your reason is for paying attention to your vitamin D levels, it’s clear this nutrient deserves our attention. Thankfully, the best source of vitamin D3 is free! All it takes is a little bit of clear skies on a sunny day.

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This information is only for educational purposes and is not medical advice or intended as a recommendation of any specific products. Consult your health care provider for more information.

References

1. Oregon State University. “Vitamin D.” 2021. Linus Pauling Institute, Micronutrient Information Center. Accessed on: June 22, 2021. https://lpi.oregonstate.edu/mic/vitamins/vitamin-D
2. Liu X, et al. Vitamin D deficiency and insufficiency among US adults: prevalence, predictors and clinical implications. British Journal of Nutrition. 2018;119(8):928-936. https://pubmed.ncbi.nlm.nih.gov/29644951/
3. Devarshi PP, et al. Total estimated usual nutrient intake and nutrient status biomarkers in women of childbearing age and women of menopausal age. Am J Clin Nutr. 2021;113(4):1042-1052. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8023996/
4. Reider CA, et al. Inadequacy of Immune Health Nutrients: Intakes in US Adults, the 2005-2016 NHANES. Nutrients. 2020;12(6):1735. https://pubmed.ncbi.nlm.nih.gov/32531972/