Vitamin D Has Many Benefits, But Preventing Diabetes Isn't One Of Them

Vitamin D is a heavy-hitter in the vitamin world. It's best known for its crucial role in promoting bone growth and strength, but research shows it may also play a role in the prevention of multiple diseases and reducing depression and mood instability (via Healthline). One area that's gotten quite a bit of attention from researchers — but has produced a mixed bag of results — is vitamin D and its potential to prevent diabetes.

Vitamin D is sometimes called the "sunshine vitamin" because the body produces it when skin is exposed to sunlight. It can also be obtained through certain foods, including egg yolks, canned tuna, sardines, and vitamin D-fortified products like breakfast cereal and orange juice. For many — especially those living in the northern hemisphere or who spend a lot of time indoors — vitamin D deficiency is common (via MedicalNewsToday).

Recently, researchers in Japan conducted a study in which they gave 630 individuals a daily vitamin D supplement and 626 individuals a placebo for three years. All of the participants had impaired glucose tolerance and were tested for diabetes every three months. The results showed no significant differences in the number of diabetes cases developed between the two groups (via U.S. News & World Report).

A 2019 study published in the European Journal of Endocrinology concluded that daily supplementation with 5,000 international units (IUs) of vitamin D significantly increased insulin sensitivity in patients who were at high risk of developing type 2 diabetes. Other studies have produced inconclusive results, raising questions about ideal dosing, and whether age, along with racial and ethnic background, factor into determining the best treatment for individual patients.

Cases of both type 1 and type 2 diabetes have increased nearly fourfold since 1980, making diabetes prevention and treatment an urgent public health issue (via MedicalNewsToday). Seek medical advice if you're considering vitamin D supplementation, as the vitamin can interfere with certain medications, and taking too much of it can be harmful. "Taking high doses of vitamin D for long periods of time can lead to some troubling side effects, especially higher levels of calcium in the blood," registered dietitian Jennifer Smith told Healthline. "Talk to your doctor, get your levels tested. The appropriate approach to vitamin D supplementation can be determined from there."