Foods to Promote Bone Health

Q:

As I'm getting older, I am becoming more concerned with bone health. Are there certain foods I can eat to fend off weakened bones?

A:

Nutrition is an important part of building and maintaining bone health. Bone is made of collagen and a complex of the minerals calcium and phosphate that provide strength to the collagen framework. Up to age 30, it is possible to continue to add new bone. However, once we pass over this bridge, our ability to accrue new bone mass stops. During the early stages of menopause, a woman's bone mass declines steeply; in the first five to seven years after menopause you can lose up to 20 percent of your bone mass. The greater your bone mass before menopause, the better your chances of avoiding fractures after menopause.

Although your genes are largely responsible for determining your peak bone mass, what you eat, the amount you eat, and the type of exercise you do can have a significant effect. The two major nutrients needed to maintain healthy bones are calcium and vitamin D. In addition, sodium, potassium and possibly protein play roles in maintaining bone health.

Over 99 percent of the body's calcium is stored in the bone. Depending on your age, you will need 1,000 to 1,200 milligrams of calcium a day. Foods high in calcium include dairy products, certain leafy green vegetables, calcium-treated tofu products and sardines with bones. Calcium is also added to some juices and fruit drinks. If you do not consume adequate amounts of calcium from food, supplements containing calcium carbonate or calcium citrate are available. You should not exceed 2,500 milligrams of calcium per day from all sources.

Vitamin D helps metabolize calcium. New research shows that the amount of vitamin D we need may be more than previously thought. Food sources of vitamin D are limited. Some sources include fatty fish, cod liver oil, egg yolks, fortified milk and other fortified foods. Vitamin D can also be generated by getting out in the midday sun for 15 minutes at least twice a week. In northern climates during the winter, the sunshine is not adequate to generate vitamin D, and most health care providers suggest supplementation if you don't regularly consume fortified milk products. Recommendations for vitamin D intake are 600 international units (IUs) up to age 71 and 800 IUs for those 71 and older.

Excess sodium intake, low potassium intake and, more controversially, excess protein intake have been shown to increase calcium excretion. These negative effects are reduced when individuals consume adequate calcium. Avoiding foods containing large amounts of sodium, such as canned products, frozen dinners, chips and highly salted condiments, can help reduce sodium intake. To ensure that you are getting your potassium for the day, eat five or more servings of a variety of fruits and vegetables.