SUMMARY

Boron occurs in foods as borate and boric acid. Boron has not been established to be an essential nutrient for humans and no specific biochemical function for boron has been identified in higher animals or man. There is some evidence that, in humans, boron intake within the usual dietary range may influence the metabolism and utilisation of other nutrients, particularly calcium, and may have a beneficial effect on bone calcification and maintenance. Recommended intakes for boron have not been established. Studies of dietary deprivation of boron in animals have reported adverse effects (e.g. on growth, serum steroid hormone concentrations and bone calcification) that can be corrected by increasing boron intake. The effects of low boron intakes are more marked when accompanied by low status for other nutrients (e.g. vitamin D, magnesium). Data on boron intake in EU countries are limited. In the UK mean intake in adults from food is estimated at 1.5 mg/day, with the 97.5 percentile of 2.6 mg/day, while mean intake from water is estimated to be in the range of 0.2-0.6 mg/day. The main dietary sources of boron are plant foods, and foods rich in boron include fruits, leafy vegetables, mushrooms, nuts and legumes, as well as wine, cider and beer. Supplements may contain 1.5-10 mg boron/dose