Since the 1930s, vitamin D has been added to milk. Now it’s available in a wide variety of supplements to address one of the nation’s most common deficiencies. But why is vitamin D important?

For one thing, it can help a wide variety of conditions: high blood pressure, depression, fatigue, osteoporosis, and cancer to name a few. Vitamin D deficiency is associated with the risk for colon, breast, ovarian, and prostate cancer.[1] A recent study found that if you have a high level of vitamin D when diagnosed with cancer, you will be more likely to survive the cancer and avoid relapse.[2]

But that’s just the beginning. It may very well help you live longer, too. A new study in the American Journal of Public Health confirmed that lower serum 25(OH)D concentrations (a measure of vitamin D levels) are linked to higher all-cause mortality rates. The study found that people whose vitamin D concentrations were in the lowest quartile (less than 9 ng/mL) had twice the death rate as those in the highest quartile (greater than 35 ng/mL) after adjusting for age. The authors conclude that “serum 25(OH)D concentrations of less than 30 ng/mL may be too low for safety.”[3]

Fixing vitamin D deficiency

While we can get vitamin D through diet or supplementation, the main source of vitamin D in our bodies is produced in the skin when it is exposed to ultraviolet B rays from the sun. People who live in climates with less sun tend to have lower vitamin D levels, as do women and elderly people.[4]

The lower limit for vitamin D in the blood should be at least 30 ng/mL.[3] Keeping your levels above this number, and even higher (between 40 and 60 ng/mL) should help you to avoid many health conditions and stay in optimum health.

Work with your doctor to manage your vitamin D levels. If you are deficient, you should highly consider taking a supplement to boost your levels. Researchers believe that only 1,000 IU daily should put your 25(OH)D value above 30 ng/mL, and supplements of 2,000 to 4,000 IU a day should increase serum vitamin D levels by 20 to 40 n/mL.[3]

Safe sun exposure can also help to keep your vitamin D in the target range. Short, small doses of sun on your skin can actually be helpful, not hurtful. Limit your time in the sun and always avoid getting burned. Wear sunscreen if you plan to be out in the sun for extended periods of time.

Share your experience

Do you take a vitamin D supplement? Have you felt your health improve as your vitamin D levels rise? Share your experience in the comments section below.

[1] Am J Public Health. 2006 Feb;96(2):252-61.

[2] J Clin Endocrinol Metab. 2014 Apr 29:jc20134320.

[3] Am J Public Health. 2014 Aug;104(8):e43-50.

[4] BMJ. 2014 Jun 17;348:g3656.