An estimated 75 percent of kids and adults are at risk of vitamin D deficiency, according to "Scientific American" Magazine. Vitamin D is produced in the body when ultraviolet rays from the sun hit your skin. Because it's a fat-soluble vitamin, the body can store excess amounts. The problem is that between wearing sunscreen and spending less time outdoors, Americans are not getting enough of the sunshine vitamin. Getting too little vitamin D is associated with brittle bones, but getting too much can lead to a health problems as well.
Vitamin D Toxicity
According to the Vitamin D Council, getting too much vitamin D can be harmful. It's impossible to get too much through UVB rays from the sun, or even a tanning bed, because of a built-in mechanism in the body. If you're taking supplemental vitamin D for fear of deficiency, however, you could be at risk of toxicity if you're taking excessive amounts over a long period of time. While the amount that constitutes a toxic level has yet to be determined, the Vitamin D Council reports that two cases of vitamin D toxicity occurred in patients who took more than 40,000 international units of vitamin D.
Symptoms
Symptoms of vitamin D toxicity include nausea, vomiting, poor appetite, constipation and/or diarrhea, weakness, weight loss, confusion and heartbeat abnormalities. Symptoms of a vitamin D overdose are gastrointestinal cramps, nausea and vomiting. Taking vitamin D regularly can help strengthen bones, but taking too much has not been linked to any kind of bone or joint pain.
Deficiency
Vitamin D deficiency has been linked to bone pain. In kids, vitamin D deficiency can lead to rickets. In adults, the condition goes by the name osteomalacia. In both cases, sore bones and body aches are primary symptoms. Taking vitamin D can reverse the condition in several weeks. While vitamin D does directly and positively affect bone health, taking too much does not have the same impact on bones as taking too little.
Warnings
Vitamin D deficiency is much more common than toxicity. Vitamin D is one of the few vitamins that is not naturally abundant in the food we eat, which is why a program was developed in the 1930s to add vitamin D to food. Today, cereal, orange juice, milk and many other foods are fortified with vitamin D. People who wear sunscreen every day may be effectively warding off dangerous melanomas, but you could also be putting yourself at risk for vitamin D deficiency. Wearing SPF 15 sunscreen, according to Dr. Adit Ginde, an assistant professor at the University of Colorado School of Medicine, reduces your vitamin D absorption significantly. The health consequences of getting too little vitamin D are especially concerning to women, who are at higher risk for developing brittle bones later in life. Overloading on a vitamin D supplement, however, is not necessary. Getting just 15 to 20 minutes of direct sunlight a day, without wearing sun block, provides sufficient amounts of the sunshine vitamin.
References
- "Scientific American"; Vitamin D Deficiency Soars in the U.S.; Jordan Lite; 2009
- Office of Dietary Supplements: Vitamin D
- FamilyDoctor.org: Rickets: What Is It and How It's Treated; November 2010
- ABC News: Does Sunblock Prevent You From Getting Vitamin D?; February 2009
- MayoClinic.com: Vitamin D Toxicity; What If You Get Too Much?; December 2010
- Vitamin D Council; Vitamin D Toxicity; June 2011
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