The recommendation in the United States is 1,000 milligrams (mg) of calcium per day for people ages 19 to 50. People over 50 need 1,200 mg per day.
These amounts are probably more than we need. In the United Kingdom, the recommendation is only 700 mg per day. The World Health Organization says that 500 mg daily is enough.
An article published in the May 24, 2011 issue of the British Medical Journal suggests that the English have it right. Researchers found that women who had a calcium intake of 700 mg per day had a similar risk of fracture and thin bones compared to women who took in much more calcium daily.
Recently some studies have raised concern about harmful effects of too much calcium. Calcium intake of more than 2,000 mg per day in men is associated with a greater risk of developing a more aggressive type of prostate cancer. Women that ingest more than 2,500 mg per day appear to have more heart disease and may have a slightly increased risk of ovarian cancer. But these studies are not definitive.
I only recommend calcium supplements for people that are not sure they average 700 mg of dietary calcium daily. For reference, an 8-ounce glass of milk or calcium-fortified orange juice has about 300 mg of calcium.
Good dietary sources of calcium include:
- Dairy products, such as milk, yogurt and low-fat cheese
- Fish with soft bones that you eat, such as sardines or salmon
- Legumes, such as beans, peas, and lentils
- Green leafy vegetables, such as broccoli, kale and cabbage
The official recommendation for vitamin D is 600 International Units (IU) daily for those under age 70. If you are older than 70, the recommendation is 800 IU per day.
There are not many good dietary sources of vitamin D. Milk is the most common source in the American diet. A glass of milk or vitamin-D-fortified orange juice contains 100 IU.
Sunlight converts inactive vitamin D in the skin to the active form. But many people rightly avoid the sun to prevent skin damage and certain skin cancers. So, I recommend a daily vitamin D supplement.
Studies have shown an association between higher blood levels of vitamin D and lower rates of breast, prostate and pancreatic cancer compared to people with low blood levels of the vitamin. Also, a similar association has been shown for higher blood levels of vitamin D and lower rates of heart disease and multiple sclerosis. None of the studies prove that vitamin D supplements prevent any of these diseases.
For most adults, I recommend a daily vitamin D supplement containing at least 400 IU daily, but no more than 1,000 IU daily.