In a clinical study, Essential for Women 18+ was shown to increase vitamin D levels by 43% over 12 weeks—significantly greater than placebo.

Sure, we may recognize vitamin D’s significance when it comes to health—it supports normal immune function and muscle function, not to mention bone health and calcium absorption—but when it comes to actually getting enough of this essential nutrient, the reality is far from sun and games.*

Why the discrepancy? A few reasons, actually. First, there’s lifestyle factors like urban dwelling, office jobs, and even sunscreen use (which is a very good thing, BTW)—all of which can hinder the ability to reach and maintain optimal vitamin D levels. Environmental elements also play a part; after all, it’s much easier to catch some rays during July than it is in the dead of winter. And when you consider the nutritional side of things—research shows that more than 93% of men and women ages 19-50 are not consuming enough vitamin D from their diets—it adds up to a fairly… grey picture. (1, 2)

On the bright side? There’s a supplement for that.

How Much Vitamin D Per Day Is Recommended?

According to the Institute of Medicine (IOM), the recommended dietary allowance for vitamin D is 15 mcg per day (or 600 International Units, aka IU) for men and women over 18. For older adults ages 70 and older, the recommended amount of vitamin D is set a little higher, at 20 mcg (or 800 IU). (3)

FYI: The amount of vitamin D can be expressed in micrograms or International Units (IU). One microgram of vitamin D is equal to 40 IU—so 10 micrograms of vitamin D would equate to 400 IU.

That said, recent research suggests higher doses may be helpful in supporting vitamin D levels—particularly for those of us experiencing those previously-mentioned lifestyle factors, or have darker skin—which is why we include 2,000 IU of vitamin D3 in our multivitamins.* (4)

Is Vitamin D Supplementation a Good Idea?

The short answer: Even if you live somewhere with plenty of rays, it’s certainly a smart way to shore up any gaps—especially when you consider national data, which shows that approximately 65% of us don’t get enough Vitamin D from diet and sun exposure combined.* (5)

Here’s the thing: Very few foods naturally contain vitamin D, much less in high dosages. The best sources of vitamin D are found in the flesh of fatty fish (salmon, trout, tuna, mackerel, sardines) and fish liver oil. Beef liver, egg yolks, cheese, and mushrooms also contain vitamin D in varying amounts. (3)

But incorporating vitamin D-rich foods—in the amount needed to meet optimal levels of vitamin D—is not as easy as it sounds: You’d have to eat a pretty considerable amount daily, and even then, it may not be a guarantee. “There can be variation depending on the type of salmon,” points out Dr. Michelle Davenport, PhD, a registered dietitian and member of Ritual’s Scientific Advisory Board. “Farmed salmon may contain as little as 25% of the D3 typically found in wild salmon.”* (6)

→ Essential reading: Vitamin D and Pregnancy: Here’s What to Consider

How to Pick a High-quality Supplement

For those looking to increase their daily intake of vitamin D through supplementation, here are some tips for picking a high-quality option.

• Look for clinical testing. Third-party quality research is one of the best methods to quantify a formula’s impact (and ensure it actually performs as intended). Take Essential for Women 18+, which was shown in a university-led clinical trial to improve vitamin D levels by 43% over 12 weeks.*
• Read the labels. There are two types of vitamin D. In a supplement, D3—also known as cholecalciferol—is the way to go, since most evidence shows that vitamin D3 has a greater impact on serum 25(OH)D levels, the main indicator of vitamin D status. Some brands offer D2, so keep your eyes peeled.* (3)
• Mind the capsule. It’s not just what’s on the inside that counts. Look for delayed-release capsules, which are designed to dissolve later, in the small intestine—an ideal place for nutrient absorption.* (3)

Of course, if you have any concerns about vitamin D levels or daily vitamin D supplementation in general, we recommend speaking to a trusted healthcare provider.

References:

1. U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2015 – 2020 Dietary Guidelines for Americans. 8th Edition. 2015.
2. USDA, Agricultural Research Service. Usual Nutrient Intake from Food and Beverages, by Gender and Age, What We Eat in America, NHANES 2013-2016. 2019.
3. National Institutes of Health Office of Dietary Supplements. Vitamin D Fact Sheet for Health Professionals. Retrieved from National Institute of Health
4. Talwar, SA; Aloia, JF; Pollock, S; Yeh, JK. 2007, December. Dose response to vitamin D supplementation… Am J Clin Nutr. 2007 Dec;86(6):1657-62. Retrieved from National Institute of Health
5. Cui A, Xiao P, Ma Y, Fan Z, Zhou F, Zheng J, Zhang L. Prevalence, trend, and predictor analyses of vitamin D deficiency in the US population, 2001–2018. Front Nutr 2022; 9: 965376. doi: 10.3389/fnut.2022.965376
6. Jakobsen, J., Smith, C., Bysted, A., & Cashman, K. D. (2019). Vitamin D in Wild and Farmed Atlantic Salmon (Salmo Salar)-What Do We Know?. Nutrients, 11(5), 982.