Boron

Type: Periodic Element
Periodic Element: (B)
RDA: Not established
Importance- To Body:
Boric acid has antiseptic, antifungal, and antiviral properties and for these reasons is applied as a water clarifier in swimming pool water treatment. Mild solutions of boric acid have been used as eye antiseptics.
Distribution- In Body:
Adult dietary intake is estimated at 0.9 to 1.4 mg/day, with about 90% absorbed. What is absorbed is mostly excreted in urine. The Tolerable Upper Intake Level for adults is 20 mg/day.
Excess Effects:
Elemental boron, boron oxide, boric acid, borates, and many organoboron compounds are relatively nontoxic to humans and animals (with toxicity similar to that of table salt). An intake of 4 g per day of boric acid was reported without incident, but more than this is considered toxic in more than a few doses. Intakes of more than 0.5 grams per day for 50 days cause minor digestive and other problems suggestive of toxicity.
Boranes (boron hydrogen compounds) and similar gaseous compounds are quite poisonous. As usual, it is not an element that is intrinsically poisonous, but their toxicity depends on structure.
Deficiency Effects:
A small human trial published in 1987 reported on postmenopausal women first made boron deficient and then repleted with 3 mg/day. Boron supplementation markedly reduced urinary calcium excretion and elevated the serum concentrations of 17 beta-estradiol and testosterone.
A report given by E. Wayne Johnson et al. at the 2005 Alan D. Leman Swine Conference suggests that boron deficiency produces osteochondrosis in swine that is correctable by addition of 50 ppm of boron to the diet. The amount of boron required by animals and humans is not yet well established.
Sources Food:
Boron is necessary for plant growth, but an excess of boron is toxic to plants, and occurs particularly in acidic soil. It presents as a yellowing from the tip inwards of the oldest leaves and black spots in barley leaves, but it can be confused with other stresses such as magnesium deficiency in other plants.
Sources Environmental/Geographic:
Boric acid is more toxic to insects than to mammals, and is routinely used as an insecticide.
Supplement Information: