Calcium in Plant-Based Diets
Many people choose to avoid milk because it contains fat, cholesterol, allergenic proteins, lactose sugar, and frequent traces of contamination. Milk is also linked to juvenile-onset diabetes and other serious conditions. Happily, there are plenty of other good sources of calcium.
Keeping your bones strong depends more on preventing the loss of calcium from your body than on boosting your calcium intake.
Some cultures consume no dairy products and typically ingest only 175 to 475 milligrams of calcium per day. However, these people generally have low rates of osteoporosis. Many scientists believe that exercise and other factors have more to do with osteoporosis than calcium intake does.
Calcium in the Body
Almost all of the calcium in the body is in the bones. There is a tiny amount in the blood stream which is responsible for important functions such as muscle contraction, maintenance of the heartbeat, and transmission of nerve impulses.
We constantly lose calcium from our bloodstream through urine, sweat, and feces. It is renewed with calcium from bone. In this process, bones continuously lose calcium. This bone calcium must be replaced from food.
Calcium needs change throughout life. Up until the age of 30 or so, we consume more calcium than we lose. Adequate calcium intake during childhood and adolescence is especially important. Later, the body begins to slip into “negative calcium balance,” and the bones start to lose more calcium than they take up. The loss of too much calcium can lead to soft bones or osteoporosis.
How rapidly calcium is lost depends, in part, on the kind and amount of protein you eat as well as other diet and lifestyle choices.
Reducing Calcium Loss
A number of factors affect calcium loss from the body:
Diets that are high in protein cause more calcium to be lost through the urine. Protein from animal products is much more likely to cause calcium loss than protein from plant foods. This may be one reason that vegetarians tend to have stronger bones than meat eaters.
Caffeine increases the rate at which calcium is lost through urine.
Diets high in sodium increase calcium losses in the urine.
Alcohol inhibits calcium absorption.
The mineral boron may slow the loss of calcium from bones.
Exercise slows bone loss and is one of the most important factors in maintaining bone health.
Sources of Calcium
Exercise and a diet moderate in protein will help to protect your bones. People who eat plant-based diets and who lead an active lifestyle probably have lower calcium needs. However, calcium is an essential nutrient for everyone. It is important to eat calcium-rich foods every day.
The “Calcium in Foods” chart on the following page gives the amount of calcium found in some excellent plant sources. A quick glance shows how easy it is to meet calcium needs. The following sample menus each provide close to 1,000 milligrams of calcium.