Boron is an essential trace mineral that is increasingly recognised as a critical regulator of the steroid hormone metabolism and of the vitamin D function — it is a non-competitive inhibitor of the enzymes that metabolise the sex hormones (including the aromatase, which converts the testosterone to the oestradiol, and the 17beta-hydroxysteroid dehydrogenase, which converts the androstenedione to the testosterone) and it is required for the optimal function of the vitamin D receptor (VDR) and for the activation of the vitamin D-dependent gene transcription. Boron is present in the body in concentrations of approximately 0.3-0.7mg/kg of body weight (with the highest concentrations in the bone, the nails, and the hair), and it is obtained from the diet (particularly from the dried fruits, the nuts, the avocados, and the dark leafy vegetables) at typical intakes of 1-7mg daily. The boron deficiency is thought to be common (because the typical dietary boron intake is often below the optimal intake for the steroid hormone and the vitamin D function), and it is associated with the reduced testosterone and oestradiol levels, the impaired calcium absorption, the reduced bone mineral density, and the impaired cognitive function — all of which are the hallmark of the boron deficiency and which are reversed by the boron supplementation at 3-10mg daily.
Boron and the Sex Hormone Metabolism
Boron is a non-competitive inhibitor of the aromatase enzyme (which converts the testosterone to the oestradiol) and of the 17beta-hydroxysteroid dehydrogenase enzymes (which interconvert the androstenedione and the testosterone and the oestrone and the oestradiol) — this inhibitory effect of boron on the sex hormone metabolism is one of the most important mechanisms of its effects on the testosterone levels, on the oestrogen levels, and on the risk of the hormone-dependent cancers (including the breast cancer and the prostate cancer). By inhibiting the aromatase, boron reduces the conversion of the testosterone to the oestradiol and thereby increases the testosterone-to-oestradiol ratio — which is beneficial for the muscle mass, for the bone density, for the libido, and for the cognitive function in men. By inhibiting the 17beta-HSD enzymes, boron modulates the balance between the androstenedione and the testosterone and between the oestrone and the oestradiol — which affects the risk of the hormone-dependent cancers and the symptoms of the menopause and the andropause.
The clinical importance of the boron for the testosterone levels is underscored by the observation that the boron supplementation increases the testosterone levels and reduces the oestradiol levels in men. A study in 8 healthy men found that the boron supplementation at 10mg daily for 6 weeks increased the serum testosterone (by 25%), increased the free testosterone (by 30%), reduced the serum oestradiol (by 40%), and increased the DHEA (by 10%) — with no adverse effects on the liver or the kidney function. These findings suggest that the boron supplementation may be an effective intervention for the men with the low testosterone and for the men who are at risk of the age-related decline in the testosterone production.
Boron and the Vitamin D Function
Boron is also required for the optimal function of the vitamin D receptor (VDR) and for the activation of the vitamin D-dependent gene transcription — it appears to be involved in the nuclear translocation of the VDR and in the recruitment of the coactivator proteins that are required for the transcription of the vitamin D target genes. By supporting the VDR function, boron enhances the effects of the vitamin D on the calcium absorption, on the bone mineralisation, on the immune function, and on the cell proliferation — all of which are the primary functions of the vitamin D. The boron deficiency impairs the vitamin D function, the calcium absorption is reduced, the bone mineralisation is impaired, and the osteoporosis develops — which is one of the most important long-term consequences of the boron deficiency and which is reversed by the boron supplementation in combination with the vitamin D and the calcium.
Practical Application
For general boron supplementation, the evidence-based approach is to supplement with 3-10mg of boron daily (as boron glycinate, boron citrate, or boron aspartate — the forms that are well absorbed and well tolerated). The typical dietary boron intake is 1-7mg daily from dried fruits, nuts, avocados, and dark leafy vegetables, and the estimated safe upper intake level is 20mg daily for adults. For comprehensive hormone and bone health support, boron pairs well with the vitamin D (which works synergistically with boron for the bone health and for the immune function), with the magnesium (which is a cofactor for the vitamin D activation enzymes and which has complementary effects on the testosterone production and on the bone health), with the zinc (which is required for the testosterone synthesis and for the bone health), and with the strontium (which is a non-radioactive isotope of strontium that has been shown to reduce the fracture risk in people with osteoporosis by promoting the bone formation and reducing the bone resorption).
Leave a Reply