The calcium conundrum: what's a body to do? - includes good sources of calcium

Vegetarian Times, July, 1997 by Suzanne Havala

In 1980, nutritionists painted a bleak picture for people who didn't drink milk. We would wring our hands with worry for the lactose-intolerant. As for anyone who harbored renegade thoughts of foregoing dairy voluntarily or finding a suitable alternative, those dreams were nipped in the bud after one glance at the calcium-equivalents list. The gist of this list was that if you didn't eat dairy products, you were doomed to enormous plates of broccoli or greens. On the other hand, if you were willing to eat sardines with bones, you were home free.

I'm so glad it's 1997. At the Third International Congress on Vegetarian Nutrition, held in March in Loma Linda, Calif., Connie Weaver, Ph.D., R.D., a professor of nutrition at Purdue University in Lafayette, Ind., put the issue in a contemporary light in her presentation about ways to ensure adequate dietary calcium. The news for vegetarians is that we have many choices.

First, a brief refresher on calcium basics. Getting enough calcium in your diet is important, especially in the first 30 years of life. It's during this time that the body builds the bone tissue that will literally carry you through your remaining years. You reach peak bone mass by the age of 35 years. After that, getting adequate dietary calcium helps you conserve the bone mass that you already have. The adequacy of your dietary calcium intake, as well as other factors, such as whether or not you smoke or engage in weight bearing exercise, and your hormone status (especially for women after menopause) affect your risk of osteoporosis, the disease that conjures up visions of women with dowager's humps and hip fractures.

The current Recommended Dietary Allowances (RDA) state that young adult men and women ages 15 to 24 years need 1,200 milligrams (mg.) of calcium per day. After 24 years, the recommendation falls to 800 mg. per day. These recommendations are based largely on data from research on white females eating a typical American diet that is characterized by high intakes of salt and protein.

Amidst all of the get-more-calcium-or-else messages that flood the media, we tend to lose sight of the fact that consumption is just one-half of the calcium equation. The other half? High intakes of salt and protein leach calcium from the bones. That's why someone on a low-salt, vegetarian diet may need less calcium than the average American. Here's how the math works:

If you like your foods salty, your bones will probably suffer. According to Weaver, every 2.3 grams (g. [2,300 mg.]) of sodium causes a loss of 40 mg. to 60 mg. of calcium. It's a good idea to hold your sodium intake to not more than about 2,000 mg. per day. That means lots of fresh, minimally processed foods such as fruits and vegetables. The closer a food is to its natural state, the less salt or sodium it probably contains.

While vegetarians typically get enough protein, they generally avoid the excessive amounts of protein found in the standard American diet. Higher protein intakes lead to higher calcium losses. Therefore, the more protein you eat, the more calcium you'll need. According to Weaver, every 1 g. increase in protein intake causes a loss of almost 2 mg. of calcium, which necessitates almost six extra grams of dietary calcium because only about 30 percent of the calcium we consume is actually absorbed. A vegetarian consuming 48 g. of protein per day would need a dietary calcium intake of 970 mg. per day to offset calcium losses due to protein. A typical American eating 90 g. of protein per day would need a calcium intake of 1,219 mg. per day to offset calcium losses due to protein.

So, how much calcium do you need? The answer to this question depends, in part, on the quality of your overall diet. Like other Americans, even vegetarians need to make an effort to limit the junk; eat plenty of vegetables; and retire the salt shaker. For now, and until research gives us a more definitive picture of the calcium needs of vegetarians, it's wise to err on the side of caution and aim for the RDA for calcium. On the other hand, even if you fall short of this recommended daily allowance, it's very likely that if you moderate your protein intake and limit your intake of sodium and salty foods, your calcium needs will be lower than those of the typical, nonvegetarian American.

Where To Get Your Calcium

Dairy products are a super-concentrated source of calcium. Unfortunately, they're also high in protein, meaning they leach calcium at the same time that they provide it. Good alternate sources of calcium include calcium-fortified soymilk and calcium-fortified fruit juice. Cup for cup, these provide the same amount of calcium as cow's milk (about 290 milligrams [mg)). Of course, drinking a fortified product is like taking a calcium supplement, which is always another option. A host of vegetables are also good sources of calcium. According to professor Connie Weaver's research, you can get the same amount of absorbable calcium in one cup of milk by eating: