Requirements
No recommendations or Daily Values have been established. Typical daily intakes in the United States vary between 0.5 milligrams to 7 milligrams. Those consuming Westernised diets consume between 0.1 to 0.5 milligrams of boron per day. 1


Signs of Deficiency
In animals (with a vitamin D deficiency) fed low amounts of boron there were increases in total calcium loss, interruption with the use of insulin, fat and glucose as well as diminished bone development. In closely monitored studies, humans fed a diet low in boron exhibited similar changes as witnessed in the boron deficient animals. Low intakes of boron may also aggravate the symptoms of arthritis. It reduces blood ionised calcium and calcitonin levels and elevates urinary calcium loss in humans, while adequate supplementation inhibits these conditions.


Interactions
Low levels of boron can cause increase urinary excretion of calcium and magnesium.


Signs of Toxicity
The majority of boron that enters the body is excreted through the urine. Boron is considered non-toxic unless consumed in excessive amounts. In animals, large doses of boron have caused loss of appetite, nausea, vomiting, skin rashes, lethargy and diarrhoea.

Current Research

Heart Disease
Researchers at the University of Sydney in Australia have found that boron might be important in reducing cardiovascular disease by inducing small increases in plasma oestrogen concentrations.6

Arthritis
Researchers at the International Symposium on Health Effects of Boron and its Compounds held at the University of California at Irvine report that boron levels in arthritic patients are low and that the arthritis rates are typically higher in regions where boron intakes are the lowest. However, in patients that supplemented their diet with boron, bone density is much greater. In one clinical trial comprised of patients with severe osteoarthritis, patients were given either 6 milligrams of boron or placebo. Half of the patients improved compared to only 10 % of subjects taking placebos.

Cognitive Function
According to the United States Department of Agriculture (USDA) Agricultural Research Center, boron is essential for mental function, hand-eye coordination, attention span, perception and short and long-term memory.5Comparing spectral analysis of electroencephalographic data of low boron intake compared to high boron intake, there was a significant increase in the proportion of low-frequency activity and a decrease in the proportion of higher frequency activity (an effect often observed in general malnutrition or heavy metal toxicity). In addition, low boron intake resulted in "significantly poorer" performance on tasks emphasising: manual dexterity, eye-hand coordination, attention, perception, encoding and short- term memory and long-term memory.5

Prostate Cancer
Researchers at the University of California at Los Angeles conclude that men whose diets had the most boron, at least 1.8 milligrams of boron per day, had less than one-third as many prostate cancers as men who consumed less than 0.9 milligrams per day.8

Immune Function
There is emerging evidence that dietary boron aids the immune system by reducing the incidence and severity of inflammatory disease. Researchers believe boron facilitates the normal inflammatory process by reducing the activity of serine proteases, enzymes that are typically elevated during the normal inflammatory process.9

Osteoporosis
Boron can help prevent against postmenopausal osteoporosis. Researchers at the Agricultural Research Service, U.S. Department of Agriculture found that women who supplemented their diet with 3 milligrams of boron excreted approximately 40 % less calcium, one-third less magnesium and slightly less phosphorous through their urine than they had prior to supplementation.4