Do you take a vitamin D supplement? Many of us do these days; testing for vitamin D deficiency has increased over the years and, along with that, an increase in the number of physicians encouraging their patients to take a vitamin D supplement in order to prevent vitamin D deficiency. Despite this, vitamin D deficiency is still a global problem, and in the U.S., estimates are that approximately 40% are deficient in the vitamin.

What does Vitamin D do for the body?

Vitamin D is well-known for its importance in bone formation and strength. A lack of vitamin D can cause bones to become brittle, thin, or misshapen. During childhood, this can lead to rickets and bone softening (called osteomalacia) in children; in adults, a vitamin D deficiency can lead to both osteomalacia and osteoporosis.

The vitamin has many other important roles in the body, including reducing inflammation and modulating cell growth, neuromuscular function, and glucose metabolism. Many of the genes involved in encoding proteins that regulate functions such as cell proliferation, differentiation, and apoptosis are also partially modulated by vitamin D.

What does Vitamin D do for the gut?

A study done in 2016 indicated that a deficiency in vitamin D is associated with a disruption in the gut bacteria and that ensuring sufficient vitamin D can improve gut health.

When it comes to the gut, vitamin D has two functions: it promotes the absorption of phosphorous and calcium – which builds strong and healthy bones. It also supports the immune function of the gut mucosa. 70% of our immune system is contained in the gut, which means Vitamin D offers support to the majority of the immune system in our bodies.

Should I take Vitamin D2 or Vitamin D3?

Vitamin D3 is the form of vitamin D the human body makes when sunlight strikes the skin, and it can also be found in food like fish oil, liver, and egg yolks. Vitamin D2 comes from mushrooms grown under UV light, and from foods that have been fortified with vitamin D. Vitamin D2 is the cheaper one to produce, it’s the one most-often added to foods and if you see a supplement that calls itself simply vitamin D, it’s most likely vitamin D2.

As it turns out, vitamin D3 does a better job at raising your body’s vitamin D levels because of the way it’s metabolized by the liver. As such, your best bet is to take a vitamin D3 supplement and, because vitamin D is fat-soluble, it’s better to choose an oil-based supplement, like a softgel, instead of a tablet.