Vitamin D works with calcium to keep your bones strong, and it also helps regulate your immune system. As little as 10 minutes of daily sun exposure can prevent a deficiency. However, it is also possible to get too much vitamin D, though this typically results from taking too many supplements and not from food or sun exposure. Your doctor can help you determine how much vitamin D is right for you and your needs.
RDA and Upper Limits
Adults between the ages of 19 and 50 need 5 mcg or 200 international units of vitamin D a day, and those over the age of 51 need 10 mcg or 400 IU. Once you are over 70, you then need 15 mcg or 600 IU of vitamin D a day. However, some researchers believe that these recommended daily allowances are too low, particularly for those who live in areas that deprive them of sun exposure. As of 2010, the National Institutes of Health has stated that the maximum upper limit of this vitamin is 2,000 IU a day for adults, but any amount over this may lead to toxicities.
Dangers of Too Much Vitamin D
Vitamin D is typically well tolerated if you consume it in adequate amounts. But if you take too much vitamin D, you can develop a number of side effects. These include poor appetite, weight loss, bone pain, exhaustion, excessive thirst, vomiting, itchy skin, sore eyes, and intestinal and muscle problems. People who have hyperparathyroidism, kidney disease, sarcoidosis, tuberculosis or histoplasmosis are at a particular risk for developing vitamin D toxicity, which may then lead to bone loss and hypercalcemia.
Importance and Sources of Vitamin D
While too much vitamin D can be dangerous, it is important that you get an adequate amount. Not only does it help with your immune system and bone strength, but low levels of vitamin D may be linked to diseases like breast cancer, high blood pressure, obesity, depression and colon cancer. Too avoid developing a toxicity, it is best to get your vitamin D through sunlight, as well as foods like fish, eggs and cod liver oil. Milk and other foods are often fortified with vitamin D as well.
Additional Considerations
If you do decide to take a vitamin D supplement, be sure to check with your doctor before doing so. Certain medications can interact with this vitamin, as well as alter your levels, and it is important to let your doctor know about any medicines or supplements that you are taking. If you experience adverse side effects while consuming vitamin D, stop taking it and seek medical attention.
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