Belief in boron: an element of strength.

Belief in boron: An element of strength

Students should no longer be taught that boron is essential only for plants, says Forrest H. Nielsen of the Department of Agriculture's Grand Forks (N.D.) Human Nutrition Research center, who has pioneered human studies of boron deficiency. Nielsen's newest work shows the element is vital to calcium metabolism in both men and women, and so may help prevent osteoporosis.

Boron deficiency could help explain why Americans display among the highest rates of osteoporosis in the world, despite consuming large quantities of calcium-rich dairy products, Nielsen says. "Maybe the reason is that we don't eat a lot of plants," he suggests. Good sources of boron are legumes, leafy vegetables and fruits, especially apples, pears and grapes.

For 63 days, Nielsen fed a low-boron diet (less than 0.32 milligram per day) to five men, five postmenopausal women on bone-preserving estrogen therapy and four postmenopausal women not on estrogen. For the next 49 days, the group ate the same diet but supplemented it with 3 milligrams per day of boron in the form of sodium borate. Nielsen designed the diet to be low in magnesium because boron's effects are more marked with magnesium deficiency.

Boron deprivation decreased blood levels of active calcium and other hormones and chemicals that influence bone metabolism. Boron supplements improved these variables as well as improving copper status. Copper is important in maintaining a healthy cardiovascular system, Nielsen says.

Safe and adequate daily boron doses range from 1 to 3 milligrams, and are easily obtained in a balanced diet, Nielsen says. He warns that taking too much boron in the form of supplements can be dangerous.