Boron is a metalloid trace element found naturally in soil, water, and certain foods — particularly fruits, vegetables, legumes, and nuts. Despite being one of the less discussed dietary minerals, boron has been identified as biologically significant for several physiological functions, though it has no established Recommended Daily Allowance (RDA) and is not classified as "essential" in the same sense as iron or zinc. Estimated adequate dietary intake is approximately 1–3 mg/day from food, with supplements typically providing 3–10 mg/day.
Bone metabolism
Boron's best-studied role relates to bone metabolism. Research in both animals and humans suggests boron influences the metabolism of minerals critical to bone — including calcium, magnesium, and phosphorus — and modulates the activity of key bone-related hormones, particularly oestrogen and vitamin D. In a classic 1987 study by Forrest Nielsen at the USDA, postmenopausal women on a boron-supplemented diet showed reduced urinary excretion of calcium and magnesium (suggesting better mineral retention) and significantly elevated levels of oestradiol and testosterone.
Hormonal effects
The most commercially promoted aspect of boron supplementation is its potential influence on testosterone levels. Several studies have examined boron's effect on sex hormone binding globulin (SHBG) — the protein that binds testosterone in the bloodstream, rendering it biologically inactive. By potentially lowering SHBG, boron may theoretically increase the fraction of free (bioavailable) testosterone. A 2011 study published in the Journal of Trace Elements in Medicine and Biology found that 10 mg/day of boron for one week significantly increased free testosterone and decreased SHBG in healthy males. However, the body of evidence is small and inconsistent.
Brain function
EEG studies from the late 1980s and 1990s (conducted by the USDA) found that boron-deficient diets correlated with decreased brain electrical activity — specifically reductions in the proportion of high-frequency (alpha and beta) brain waves and increases in low-frequency waves associated with reduced alertness and poorer cognitive performance. Boron repletion reversed these changes. While these findings have not been extensively replicated, they established a plausible role for boron in cognitive function.
Forms of boron in supplements
Boron supplements are available as several salts: boron citrate, boron glycinate, boron aspartate, and sodium borate. There is limited comparative absorption data, though organic forms (citrate, glycinate) are generally considered to be better absorbed than inorganic borates. FruiteX-B is a proprietary calcium fructoborate form marketed with some bioavailability data.
Recent research
- Effect of dietary boron on mineral, estrogen, and testosterone metabolism in postmenopausal women — FASEB Journal, 1987. Authors: Nielsen FH et al. Dietary boron deprivation reduced serum 17β-oestradiol and testosterone concentrations, both of which were restored upon supplementation.
- Comparative effects of daily and weekly boron supplementation on plasma steroid hormones and proinflammatory cytokines — Journal of Trace Elements in Medicine and Biology, 2011. Authors: Naghii MR et al. Serum testosterone rose 28.3% and free testosterone rose 14.7% after 1 week of boron supplementation in healthy males.
- Boron and arthritis: The results of a double-blind pilot study — Journal of Nutritional Medicine, 1990. Authors: Travers RL et al. Subjects in boron-supplemented regions showed significantly higher bone boron concentrations compared to control regions.
Boron in Lebanon
Supplements & More carries Horbäach Triple Boron Complex from the US, available with cash on delivery across Lebanon.