Herbs & Supplements:
Boron
Supplement Forms / Alternate Names
•
Boron Chelate, Sodium Borate
Principal Proposed Uses
•
Osteoarthritis
Other Proposed Uses
•
Osteoporosis, Rheumatoid Arthritis
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 may be helpful for arthritis and osteoporosis.
Sources
No dietary or nutritionalrequirement 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.
Therapeutic Dosages
When used as a treatment for arthritis 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).
Therapeutic Uses
Although boron is often added to supplements intended for the treatment of osteoarthritis, the evidence that it helps is very weak.1,2,3 Three othersupplements—glucosamine, chondroitin, and SAMe—are much better researched treatments for osteoarthritis.
Boron has also been suggested as a treatment for osteoporosis.4
In addition, boron is sometimes recommended as a treatment for rheumatoid arthritis, but there is no real evidence that it works.
Finally, one large observational study suggests that higher intake of boron may reduce risk of prostate cancer.5
What Is the Scientific Evidence for Boron?
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%. However, in regions where there is less boron in the diet—1 mg or less per day—the incidence of arthritis is higher.6This observation has given rise to the theory 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.7,8
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.9 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. A more recent study failed to support this finding.10
Safety Issues
Since the therapeutic dosage of boron is about the same as the amount you can get from food, it is probably fairly safe. Unpleasant side effects, including nausea and vomiting, are only reported at about 50 times the highest recommended dose.
One potential concern with boron regards its effect on hormones. In at least two small studies, boron was found to increase the body's own estrogen levels, especially in women on estrogen-replacement therapy.11,12 Because elevated estrogen increases the risk of breast and uterine cancer in women past menopause, this may be a matter of concern for those who wish to take supplemental boron.Further research is necessary to discover whether boron's apparent effect on estrogen is a real problem or not. At the present time, we would recommend getting your boron from fruits and vegetables: a large study found that high intake of boron from these sources did not affect breast cancer rates.13
Interactions You Should Know About
If you are receiving hormone-replacement therapy, use of boron may not be advisable due to the risk of elevating estrogen levels excessively.
View References
Last reviewed March 2002 by Medical Review Board
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