Most people get enough vitamin D from the sun, and there’s no evidence that taking supplements of the so-called sunshine vitamin will fight off cancer, prevent diabetes, or strengthen a person’s immune system, a panel of U.S. and Canadian doctors said on Tuesday.
The announcement comes as part of a new set of dietary intake guidelines for both calcium and vitamin D, released this week by the Institute of Medicine (IOM), an independent American health agency established in 1863.
Using expert testimony and nearly 1,000 published studies analyzing the two nutrients, the IOM discerned that most North Americans 70 years of age or under need just 600 international units (IUs) of vitamin D per day, and those over the age of 71 need 800 IUs. Calcium intake, on the other hand, can vary from 700 to 1,300 milligrams daily.
“The committee that wrote the report also reviewed hundreds of studies and reports on other possible health effects of vitamin D, such as protection against cancer, heart disease, autoimmune diseases, and diabetes,” the IOM said in a Tuesday press release. “While these studies point to possibilities that warrant further investigation, they have yielded conflicting and mixed results and do not offer the evidence needed to confirm that vitamin D has these effects.”
However, both calcium and vitamin D were proven to have positive effects when it comes to bone health and skeletal growth and maintenance, the researchers noted.
“There is abundant science to confidently state how much vitamin D and calcium people need,” Committee Chairperson Catharine Ross, a professor with the Pennsylvania State University Department of Nutritional Sciences, said in a statement. “We scrutinized the evidence, looking for indications of beneficial effects at all levels of intake. Amounts higher than those specified in this report are not necessary to maintain bone health.”
Children between the ages of 1 and 3 should consume 700mg of calcium per day, while kids between the ages of 4 and 8 should up their intake to 1,000mg, the IOM said. Individuals between the ages of 9 and 18 need no more than 1,300mg of calcium daily, while most adults between the ages of 19 and 50 can reduce their calcium intake back down to 1,000mg. Men over the age of 50 and under the age of 71 can maintain that level, while women are advised to up their consumption to 1,200mg daily.
“The majority of Americans and Canadians are getting enough vitamin D and calcium, the committee determined from reviewing national surveys of blood levels,” the IOM reported. “Some adolescent girls may not get quite enough calcium, and there is a greater chance that elderly individuals may fall short of the necessary amounts of calcium and vitamin D. These individuals should increase their intake of foods containing these nutrients and possibly take a supplement.”
Overdosing on either nutrient can be dangerous, the researchers reported. Consuming high levels of vitamin D (at least 10,000 IUs daily) are known to cause kidney and tissue damage, they claim, and even taking 4,000 IUs daily could be risky. In terms of calcium, the IOM says that taking more than 2,000mg each day could lead to kidney stones, especially in post-menopausal women.
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