Can Too Much Vitamin D Harm Your Health?

Vitamin D is often called the “sunshine vitamin” because its primary source is the sun but sometimes too much of any good thing is a bad thing. Too much vitamin D can cause an abnormally high blood calcium level, which could result in nausea, constipation, confusion, abnormal heart rhythm, and even kidney stones. Vitamin D can be obtained through three different sources: diet, sunlight and dietary supplements. While the risk of consuming too much vitamin D through diet and sunlight is virtually nonexistent, some people can overdose on vitamin D through supplementation.In fortified supplements and foods, vitamin D is present in two different forms: D-2 and D-3. Both forms of vitamin D can effectively raise the body’s levels of vitamin D. This nutrient helps the body absorb calcium and is necessary for bone growth. A lack of vitamin D can cause a number of conditions, including brittle bones, osteoporosis and rickets in children.

We believe it’s vital for you to get enough vitamin D3. If you’re chronically short, your risk goes up for an array of nastiness: several cancers (including breast, colon, and ovarian), heart disease, osteoporosis, asthma, type 1 diabetes, multiple sclerosis, and high blood pressure. New studies are also turning up links between low D and obesity in kids, injuries among pro football players, digestive diseases, pneumonia, and anemia. Vitamin D is good to a certain level. It is found in very few foods, though commercially sold milk is usually fortified with it. As people spend more and more time indoors and slather their bodies with sunscreen, concern is rising that many are vitamin D-deficient.

To determine if your vitamin D blood serum levels are too high, you can have your blood tested. Because vitamin D aids in calcium absorption, high vitamin D levels in the body can lead to a condition known as hypercalcemia, or high blood calcium. While vitamin D is not present in many foods, it does occur in significant amounts in fatty fish, such as cod, swordfish, salmon, mackerel and tuna. It can also be found in small amounts in beef liver, egg yolks and cheese. Foods such as milk, yogurt, orange juice and cereal may also be fortified with vitamin D. Cod liver oil can be consumed to obtain vitamin D, too. One tablespoon of cod liver oil contains 340 percent of the daily value of vitamin D. The National Institutes of Health notes that between five and 30 minutes of sun exposure, between the hours of 10 a.m. and 3 p.m., two times per week, without sunscreen.

Nevertheless, vitamin D deficiency is more common than you might expect. People who don’t get enough sun, especially people living in Canada and the northern half of the US, are especially at risk. Vitamin D deficiency also occurs even in sunny climates, possibly because people are staying indoors more, covering up when outside, or using sunscreens consistently these days to reduce skin cancer risk. Because certain groups may be at highest risk for vitamin D deficiency, they may also benefit most from vitamin D supplementation. These groups include breast-fed infants, older adults, those with limited sun exposure, and people with dark skin.

Celeste Botonakis

On the Nursing Assistant Guides blog, certified medical assistant Celeste Botonakis explores the daily life of a CMA. She'll keep you up-to-date with the latest on what’s happening in the field, and provides tips for those who are interested in becoming a medical or nursing assistant. Celeste has served in the medical field for over six years, and is passionate about helping people. She currently works at CSR Primary Care in Skokie, Illinois. Click here to learn more about Celeste Botonakis and