Vitamin D is sometimes called the “sunshine vitamin” because it’s produced in your skin in response to sunlight. It’s a fat-soluble vitamin in a family of compounds that includes vitamins D-1, D-2, and D-3.
Your body produces vitamin D naturally when it’s directly exposed to sunlight. You can also get it through certain foods and supplements to ensure adequate levels of the vitamin in your blood.
Vitamin D has several important functions. Perhaps the most vital are regulating the absorption of calcium and phosphorus, and facilitating normal immune system function. Getting a sufficient amount of vitamin D is important for normal growth and development of bones and teeth, as well as improved resistance against certain diseases.
If your body doesn’t get enough vitamin D, you’re at risk of developing bone abnormalities such as soft bones (osteomalacia) or fragile bones (osteoporosis).
Here are three more surprising benefits of vitamin D:
Vitamin D fights disease
In addition to its primary benefits, research suggests that vitamin D may also play a role in:
- reducing your risk of multiple sclerosis, according to a 2006 study published in the Journal of the American Medical Association
- decreasing your chance of developing heart disease, according to 2008 findings published in Circulation
- helping to reduce your likelihood of developing the flu, according to 2010 research published in the American Journal of Clinical Nutrition
Vitamin D reduces depression
Research has shown that vitamin D might play an important role in regulating mood and warding off depression. In one study, scientists found that people with depression who received vitamin D supplements noticed an improvement in their symptoms.
In another study of people with fibromyalgia, researchers found vitamin D deficiency was more common in those who were also experiencing anxiety and depression.
Vitamin D boosts weight loss
Consider adding vitamin D supplements to your diet if you’re trying to lose weight or prevent heart disease.
In one study, people taking a daily calcium and vitamin D supplement were able to lose more weight than subjects taking a placebo supplement. The scientists said the extra calcium and vitamin D had an appetite-suppressing effect.
In another study, overweight people who took a daily vitamin D supplement improved their heart disease risk markers.
Beware of D-ficiency
Many factors can affect your ability to get sufficient amounts of vitamin D through the sun alone. These factors include:
- Being in an area with high pollution
- Using sunscreen
- Spending more time indoors
- Living in big cities where buildings block sunlight
- Having darker skin. (The higher the levels of melanin, the less vitamin D the skin can absorb.)
These factors contribute to vitamin D deficiency in an increasing number of people. That’s why it’s important to get some of your vitamin D from sources besides sunlight.
Food sources of vitamin D
Few foods contain vitamin D naturally. Because of this, some foods are fortified. This means that vitamin D has been added. Foods that contain vitamin D include:
- egg yolk
- milk (fortified)
- cereal (fortified)
- yogurt (fortified)
- orange juice (fortified)
How much do you need?
There has been some controversy over the amount of vitamin D needed for healthy functioning. Recent research indicates that you need more vitamin D than was once thought. Normal blood serum levels range from 50 to 100 micrograms per deciliter. Depending on your blood level, you may need more vitamin D.