The Institute of Medicine recently warned against taking too much vitamin D, saying it could cause calcifications in your kidneys’ blood vessels and in your heart. Here’s the thing: That warning was for the rare events that happen in people taking 10,000 IU a day (that’s 10 times what I recommend daily!), plus high-dose calcium (don’t take more than 600 mg a day in a supplement). I want you to continue to take vitamin D3
and magnesium for the simple reason that your body needs them.
Your body needs vitamin D3 to get calcium where it belongs — in bone and electrically excitable cells. Besides being essential for good bone health, vitamin D3 also helps slow the progression of arthritis, hypertension
, kidney disease, arterial aging (thus decreasing risk of heart disease
and stroke), wrinkles, memory loss and impotence. Plus, D3 helps protect you from cancer.
Most American adults don’t get enough vitamin D. You can get it from three sources: the sun, food, and vitamin supplements. Here’s the first problem: Most people aren’t exposed to enough sun to get the recommended amount of D. But prolonged exposure can increase your risk of skin cancer — and wearing sunblock also blocks the vitamin D. So food and supplements make the most sense. Some foods, like fish and shellfish, have D naturally, while other foods, like milk, 100 percent natural orange juice and cereal, often are fortified with it. Since most adults don’t drink enough milk or orange juice or eat enough cereal to get the recommended dosages, supplementing your diet with D can give you the levels you need. I recommend that you take 1,000 IU of vitamin D in a supplement if you’re under 60 and 1,200 IU if you’re over 60. That’s how much is necessary for the optimal absorption of calcium and the optimal incorporation into the bone. I also recommend 400 to 500 milligrams of magnesium (a nutrient found in almonds), because magnesium helps balance the effects of calcium on nerve function.
Lastly, get your vitamin D3 levels measured. Why? Recently a leading testing center reported that of the 30 or so brands of vitamin D3 supplements tested, the average contained only 33 percent of the dose on the label — there was even variability from bottle to bottle of the same manufacturer! Make sure you get what you pay for — and what your body needs.