Boron Overview

Plants need boron for proper health, but it's not known whether humans do. However, boron does seem to assist in the proper absorption of calcium, magnesium, and phosphorus from foods, and slows the loss of these minerals through urination. Very preliminary evidence suggests that boron supplements may be helpful for osteoarthritis and osteoporosis .

No dietary or nutritional requirement for boron has been established, and boron deficiency is not known to cause any disease. Good sources include leafy vegetables, raisins, prunes, nuts, non-citrus fruits, and grains. A typical American daily diet provides 1.5 to 3 mg of boron.

When used as a treatment for osteoarthritis or osteoporosis, boron is often recommended at a dosage of 3 mg per day, an amount similar to the average daily intake from food. However, food sources may be safer (see Safety Issues ).

Osteoarthritis

In areas of the world where people eat relatively high amounts of boron—between 3 and 10 mg per day—the incidence of osteoarthritis is below 10%. ¹ However, in regions where there is less boron in the diet—1 mg or less per day—the incidence of arthritis is much higher. In addition, the joints of people with osteoarthritis have been found to contain less boron than people without the condition. These observations have given rise to the hypothesis that boron supplements might be helpful for people who already have arthritis symptoms.

However, the only direct evidence that it works comes from one highly preliminary study reported in 1990. ²

Osteoporosis

In one small study, 13 postmenopausal women were first fed a diet that provided 0.25 mg of boron for 119 days; then they were fed the same diet with a boron supplement of 3 mg daily for 48 days. ³ The results revealed that boron supplementation reduced the amount of calcium lost in the urine. This suggests (but certainly doesn't prove) that boron can help prevent osteoporosis.

However, in a similar study, boron administration did not affect urine calcium loss. ⁴ Another study found that boron fails to affect calcium loss among people who receive enough magnesium. ⁵

1. Newnham RE. Essentiality of boron for healthy bones and joints. Environ Health Perspect. 102 Suppl 7():83-5.
2. Travers RL, Rennie GC, Newnham RE. Boron and arthritis: the results of a double-blind pilot study. J Nutr Med. 1990;1:127-132.
3. Nielsen FH, Hunt CD, Mullen LM, et al. Effect of dietary boron on mineral, estrogen, and testosterone metabolism in postmenopausal women. FASEB. 1987;1:394-397.
4. Beattie JH, Peace HS. The influence of a low-boron diet and boron supplementation on bone, major mineral and sex steroid metabolism in postmenopausal women. Br J Nutr. 69(3):871-84.
5. Hunt CD, Herbel JL, Nielsen FH. Metabolic responses of postmenopausal women to supplemental dietary boron and aluminum during usual and low magnesium intake: boron, calcium, and magnesium absorption and retention and blood mineral concentrations. Am J Clin Nutr. 65(3):803-13.