Boron
A trace mineral that influences testosterone and estrogen metabolism, enhances Vitamin D levels, and supports bone health. Often absent from supplements despite important metabolic roles.
What is Boron?
Boron is an ultra-trace mineral that influences calcium, magnesium, and phosphorus metabolism and modulates steroid hormone levels. While not officially classified as 'essential' by the IOM, accumulating evidence suggests it plays important roles in bone health, hormone metabolism, and cognitive function. Boron is concentrated in bone, nails, and hair.
Known Health Benefits
How It Works
Boron inhibits 24-hydroxylase, the enzyme that degrades calcitriol (active vitamin D), thereby extending vitamin D's biological half-life. It influences sex hormone metabolism by reducing sex hormone-binding globulin (SHBG), increasing free testosterone and estradiol bioavailability. Boron participates in the hydroxylation reactions of steroid hormones and affects inflammatory mediators (reduces CRP, TNF-α, and IL-6 in studies). It also inhibits serine proteases involved in cartilage degradation.
What Research Says
A 2011 study in the Journal of Trace Elements in Medicine and Biology found that 6 mg boron daily for 60 days significantly increased free testosterone (+28%) and decreased estradiol (−39%) in healthy males. A 1987 USDA study by Nielsen showed that boron deprivation in postmenopausal women increased urinary calcium and magnesium losses, suggesting it supports mineral retention. A 2015 review in Integrative Medicine noted boron's role in wound healing, vitamin D metabolism, and cognitive performance.
Active Compounds
Boron glycinate, sodium borate, boron citrate
Forms & Bioavailability
Boron from dietary sources and supplements is absorbed at approximately 85–90% in the GI tract. It is not heavily protein-bound and distributes rapidly to tissues. Urinary excretion is the primary elimination route, and boron does not accumulate significantly at dietary or supplemental doses.
Dosage Guidance
| Use Case | Dosage |
|---|---|
| General health / bone support | 3 mg |
| Testosterone and hormone optimization | 6–10 mg |
| Vitamin D enhancement | 3–6 mg |
| Joint and arthritis support | 6–10 mg |
Always consult a healthcare provider for personalized dosing.
Natural Food Sources
- Prunes (1.18 mg per serving)
- Raisins (0.95 mg per ½ cup)
- Avocado (0.75 mg per fruit)
- Peanut butter (0.59 mg per 2 Tbsp)
- Apples (0.66 mg per medium)
- Red wine (0.36 mg per glass)
Potential Side Effects
Generally safe at low doses; toxic at high doses (>20mg/day)
Who Should Avoid It
- Hormone-sensitive cancers (breast, prostate) — boron modulates estrogen and testosterone; use with caution
- Kidney impairment — boron is renally excreted; accumulation possible
- Do not exceed 20 mg/day — UL established by WHO based on reproductive toxicity in animals
Pregnancy & Lactation
Limited human data exist for boron supplementation during pregnancy and lactation. Animal studies show reproductive toxicity at high doses (approximately 10 mg/kg/day). The WHO UL of 20 mg/day provides a wide safety margin, but supplementation during pregnancy is not routinely recommended. Dietary boron intake (1–3 mg/day) is considered safe.
Known Drug Interactions
May interact with hormone therapies and blood thinners
Evidence Classification
Based on in vitro studies, animal models, pilot trials, or traditional use documentation. Clinical evidence is limited.
Frequently Asked Questions
Can boron really increase testosterone?
Yes — a 2011 study showed 6 mg/day increased free testosterone by 28% after one week in healthy men. The mechanism is reduction of SHBG, which frees bound testosterone. However, the study was small and more research is needed.
How does boron support bone health?
Boron enhances the half-life of active vitamin D (calcitriol), reduces urinary loss of calcium and magnesium, and influences osteoblast activity. Regions with higher boron in soil and water have lower rates of arthritis.
Is boron an essential mineral?
Technically, the IOM has not classified boron as essential because a specific biochemical function requiring boron hasn't been identified in humans. However, strong evidence of its metabolic roles has led many researchers to argue it should be reclassified.
How much boron do I get from my diet?
The average American diet provides 1–3 mg of boron daily, primarily from fruits, vegetables, nuts, and legumes. Diets rich in plant foods provide more boron than animal-heavy diets.
Can I take boron with other supplements?
Yes. Boron pairs particularly well with vitamin D3, calcium, and magnesium, as it enhances their metabolism. It is commonly included in comprehensive bone-health formulas.
References
- Comparative effects of daily and weekly boron supplementation on plasma steroid hormones and proinflammatory cytokines. Naghii MR, Mofid M, Asgari AR, et al.. Journal of Trace Elements in Medicine and Biology (2011)View study
- The effect of boron supplementation on its urinary excretion and selected cardiovascular risk factors in healthy male subjects. Naghii MR, Samman S. Biological Trace Element Research (1997)View study
- Nothing Boring About Boron. Pizzorno L. Integrative Medicine: A Clinician's Journal (2015)View study
Related Health Conditions
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This entry is for educational purposes only. It is not medical advice. Always consult a qualified healthcare provider before starting, stopping, or changing any supplement regimen, especially if you take medications or have health conditions.