Your bones, immune system and many other areas of your body need vitamin D to work properly. The amount of international units, or IU, that you should take in a day will depend on your age, as well as your skin tone and where you live. While being deficient in vitamin D can harm you, taking too much poses risks as well. Discuss your intake of vitamin D with a health-care provider.
Recommended Daily Allowance and Risks for a Deficiency
According to the Office of Dietary Supplements, people between the ages of 1 and 70, including pregnant and breast-feeding women, need 600 IU of vitamin D a day. If you are over 70, your recommended daily allowance, or RDA, is 800 IU a day. Your skin makes vitamin D when it is exposed to sunlight, but certain people may be able to produce as much as others. These include older adults, whose skin does not absorb sunlight and make vitamin D as efficiently as when they were younger. People who have darker skin tones also do not absorb as much sunlight as those with lighter skin tones. Additionally, people who live in climates with infrequent sun may also not be getting enough vitamin D.
Sources and Supplements
In addition to sunlight exposure, you can eat foods and take supplements to meet your RDA of vitamin D. Not many foods naturally contain vitamin D, though fatty fish, beef liver and mushrooms are good sources. Nearly all of the milk in the United States is fortified with 400 IU of vitamin D for each quart, and many cereals are fortified with this vitamin as well. Finally, multivitamins often contain vitamin D, or you can take it as an individual supplement. Speak with your doctor about the types and IU doses of supplements that you should take.
Importance and Deficiency
You need to meet your RDA of vitamin D for a variety of reasons. For one, this vitamin helps your body make use of calcium, which in turn strengthens your teeth and bones. Vitamin D also regulates and maintains the cells in your immune system, and this may help prevent certain types of cancer. Not getting enough vitamin D as a child can result in a condition known as rickets, or soft bones. As an adult, a deficiency can lower your bone density, decrease your blood calcium levels and even increase your risk of falling and incurring fractures.
Upper Limits and Additional Considerations
While vitamin D is essential, taking too much can result in adverse effects like kidney stones, confusion, constipation and vomiting. Vitamin D toxicity typically occurs when you take too many supplements, rather than from your intake of food or exposure to sunlight. To avoid these and other side effects, do not consume more than a combined total of 4,000 IU a day from your foods and supplements. If you are concerned about your vitamin D intake, consult with your health-care provider.
Member Comments