Abstract
- Background
Boron is a trace element that plays an important role in numerous biological functions, including calcium metabolism, growth, and maintenance of bone tissue. However, there are still no precise indications regarding a possible role of boron supplementation—and its specific dosage—in maintaining bone health. The aim of this narrative review was to consider the state of the art on the effectiveness of boron supplementation (alone or with other micronutrients) on the growth and maintenance of bone in humans through the control of calcium, vitamin D, and sex steroid hormone metabolism in order to suggest a daily dosage of boron supplementation.
- Methods
A narrative review was conducted to retrieve clinical studies evaluating the impact of oral boron supplementation on human skeletal metabolism and bone maintenance. Eligible studies included randomized controlled trials, interventional clinical trials, and epidemiological studies evaluating boron alone or in combination with other micronutrients. Out of the retrieved literature, 11 studies encompassing a total of 594 human subjects met the inclusion criteria and were analyzed.
- Results
This review included 11 eligible studies: 7 regarding supplementation with boron alone and 4 regarding supplementation with boron combined with other nutrients. Despite the limited number of studies, the total participant pool was substantial ($N = 594$). Data demonstrated that dietary supplementation with $3\text{ mg/day}$ of boron (alone or in combination) significantly improved bone maintenance by regulating calcium retention, elevating active vitamin D levels, and optimizing sex steroid hormone concentrations. This $3\text{ mg/day}$ dose proved to be clinically effective and is well below the Tolerable Upper Intake Level ($\text{UL}$) of $10\text{ mg/day}$ established by the European Food Safety Authority ($\text{EFSA}$).
- Conclusions
The studies considered in this narrative review demonstrate that dietary supplementation with $3\text{ mg/day}$ of boron (alone or with other nutrients) positively affects human bone health through the modulation of calcium, vitamin D, and sex steroid hormone metabolism. This daily dose is demonstrably useful to support bone health and maintain adequate bone mineral density, offering a safe intervention far below the $\text{EFSA}$ upper intake threshold.
https://www.sciencedirect.com/science/article/pii/S0946672X20301425