93% Of People Have A Vitamin D Deficit—Here's How To Supplement

What essential nutrient deficit affects over 90% of the population1 and rarely gets diagnosed? If you answered vitamin D, you're correct.

Vitamin D is a hormone-like micronutrient produced from a photolytic reaction with ultraviolet (UV) light—which can be hard to come for those of us who spend a lot of time indoors.

Many of us live in more northern latitudes (pretty much anywhere north of Florida), where ample sunlight is not available year-round.

Even for those who do have access to lots of sun, many folks spend the majority of time indoors or slather on UV-blocking sunscreen when they do go out.

As you get older, your body also naturally slows down its production of natural vitamin D (skin photosynthesis becomes much less efficient).

The average 70-year-old creates significantly less vitamin D3 than a younger person.

Skin color makes a difference, too, as people with darker skin (i.e., more melanin) produce less vitamin D.

While there are some vitamin-D-rich foods, including fungi-yeast (D2), UV-treated mushrooms (D2), and liver (especially from oily fish like cod, herring, and sardines) providing D3, most don't have high enough levels of the hormone.

Unless you're eating 30 ounces of wild salmon a day (i.e., 7 plus servings of fish) or downing 5 plus tablespoons of cod liver oil with breakfast, you might need to start taking a supplement to make sure you're getting optimal levels.*

The National Academies recommends4 the general population consume 400 to 800 IU of vitamin D a day. That's 400 IU for infants, 600 IU for those ages 1 to 70, and 800 IU for individuals older than 70. To be clear: That is the amount to prevent frank vitamin D deficiency and two serious clinical bone mineralization defects, rickets and osteomalacia, which are directly caused by vitamin D deficiency and require medical attention.

Use D3, not D2 (because D3 is significantly more efficacious than D2).* Vitamin D3 is typically derived from lanolin, so strict vegans should find an algal-derived D3, preferably ones that's sourced with sustainability in mind.

If you have an insufficiency or deficiency, correct it with 5,000 to 10,000 IU of vitamin D3 a day for three months—preferably in partnership with your healthcare provider.*

Since everyone is a unique individual, genes and all, vitamin D status and response to supplementation can vary, and obviously seasonal changes affect it too.

There are different "optimal ranges." Experts and organizations have different ranges. You want your 25(OH)D levels well over 30 ng/ml. This is the cutoff for clinical insufficiency. Rechecking your levels after three months (and periodically beyond that) is the clinical consensus.

It could take six to 10 months to "fill up the tank" for vitamin D if you're deficient.* Once this occurs, you can lower the dose to a maintenance dose.