Getting the most from calcium

Whatever the dietary source of calcium, it must be absorbed properly for it to be beneficial. Certain nutrients can play a positive or negative role.

Vitamin D helps calcium absorption. Fatty fish, eggs, liver, multivitamins, fortified milk and even direct sunlight are good sources.

Some nutrients that interfere with calcium absorption:

• Sodium, because it increases calcium excretion.

• Caffeine, but the slight loss can be rectified by adding a small amount of milk or cream to coffee.

• Too much protein, because excess protein creates sulfates, which increase the amount of calcium excreted in urine.

• Oxylates, which, ironically, are found in high-calcium foods such as spinach, sweet potato, collards, beans and rhubarb. But the oxylates affect the absorption of calcium in the food itself, and not with calcium-rich foods eaten at the same time: the cheese or milk in creamed spinach, for example. Tea also contains oxylates, so it is not a good idea to drink it at the same time you are eating calcium-rich foods.

• Phosphorus, a component of colas and some processed foods, may inhibit calcium absorption, although some scientists think that the detrimental effects have to do with replacing milk with soda.

In addition to foods, says nutritionist Tamara Swett, other factors decrease calcium absorption, like prednisone and other medications and loss of estrogen.

Smoking, stress and lack of exercise may also contribute to the body not being able to absorb calcium effectively.

Swett emphasizes the importance of exercise in preventing osteoporosis. Weight-bearing exercise helps maximize bone strength by making bones and muscles work against gravity. Good examples of weight-bearing exercises are walking, running, dancing, aerobics and skating.

Ronnie Fein, The Stamford Advocate