Boron is a non-metallic mineral present in the human body in trace amounts. Dietary boron influences the activity of many metabolic enzymes, certain hormones, and the metabolism of several micronutrients, including calcium, magnesium, and vitamin D. However, the biological function of boron in humans has not yet been clearly established.
Boron may play a role in osteoporosis prevention by reducing calcium excretion and increasing deposition of calcium in the bone.
Studies with animals and humans indicate that some ninety percent of boron is absorbed in the normal intake range. Most dietary boron is hydrolyzed within the gut to yield B(OH)3 which, as a neutral compound, is easily absorbed.
The best dietary sources of boron are fruit-based beverages and products, tubers, legumes, nuts, dried fruits, fresh fruits, and fresh vegetables.
No data are available on adverse health effects from ingestion of large amounts of boron from food and water. The tolerable upper intake level (UL) has been set at 20 mg per day for adults.