General Description
Boron is a nonmetallic element discovered in 1810 and first isolated
in its pure form in the late 1800s. Found only in trace amounts
in the human body, boron was generally viewed as a nonessential
mineral; however, research conducted over the last twenty years
suggests that boron may play important roles in mineral metabolism,
hormone synthesis, and brain function. Supplemental forms of boron
include boron chelates (such as boron citrate, aspartate, and glycinate),
sodium borate, and sodium tetraborate decahydrate.
Food sources
Small amounts of boron are present in nearly all plants and animals.
Good sources of boron include nuts, dried fruits, wine, peanut
butter, legumes, and fresh fruits and vegetables. However, the
boron content of foods depends on the boron content of the soil,
which varies greatly from region to region.1
Health applications
Deficiency symptoms
Although there are no documented cases of overt boron deficiency,
boron depletion has been linked to poor manual dexterity, eye-hand
coordination, attention and short-term memory, depressed growth,
and reduction of steroid hormone levels.2-4
Osteoporosis
Numerous studies show that boron plays a role in the absorption
and utilization of calcium and magnesium, suggesting potential
benefit in the prevention of osteoporosis.5-9
Studies also indicate that boron supplementation can have a favorable
influence on the levels of certain hormones associated with bone
loss in postmenopausal women.9,10
Osteoarthritis
Preliminary evidence suggests that boron may have an impact on
the development of osteoarthritis. Researchers have observed a
higher incidence of arthritis in populations consuming boron-depleted
foods compared to people consuming boron-rich diets.1
Investigations on bone composition have shown that bones adjacent
to arthritic joints tend to have significantly lower boron content
than bones adjacent to healthy joints.11 In one small
study, 50 percent of arthritic subjects given 6 mg of boron per
day showed significant improvement in symptoms compared to 10
percent for a placebo group.12 Further, large-scale
studies are needed to determine the potential for boron in the
treatment of osteoarthritis.
Dosage/toxicity
The optimum daily intake for boron has not been determined. Normal
boron intake from foods varies widely from region to region, with
estimated intakes ranging from 0.3 to 41 mg per day.4
The average dietary boron intake for Americans is estimated to
be 1.02 mg/day for men and 0.96 mg/day for women.13
Studies on boron supplements have used doses of 3 to 6 mg per
day, and this dosage range appears to be safe for most people.
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