Boron

mineralboron atom

What is it

Boron is a trace mineral found in fruits, vegetables, nuts, and legumes. It is not formally classified as an essential nutrient for humans, but evidence suggests it influences bone health, mineral metabolism, and certain hormonal pathways.

How it works

Boron is absorbed in the small intestine and circulates primarily as boric acid. It appears to influence the metabolism of several minerals (calcium, magnesium, phosphorus) and steroid hormones (estrogen, testosterone, vitamin D), potentially by inhibiting certain enzymes and modifying membrane function. Boron-containing compounds also play structural roles in plant cell walls, although the corresponding human role is less well-defined. In experimental human studies, low-boron diets followed by supplementation have shown effects on calcium balance, serum steroid hormones, and certain inflammatory markers. The exact biochemical targets in humans remain an active area of research, and the body's requirement for boron is not formally established.

Evidence for 5 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Bone health and mineral balance

Grade C

Moderate evidence

Boron supplementation (3 mg/day) has been shown in small studies to reduce urinary calcium and magnesium losses, particularly in postmenopausal women with low intake. Whether this translates to fracture reduction is unproven.

Osteoarthritis

Grade C

Moderate evidence

Some small trials and observational data suggest boron may modestly improve joint comfort. Mechanisms could involve anti-inflammatory effects or mineral metabolism. Evidence is limited.

Steroid hormone modulation

Grade C

Moderate evidence

Short-term supplementation has been shown to raise serum estradiol in postmenopausal women and modestly raise free testosterone in men in small studies. Clinical significance is uncertain.

Cognitive function

Grade D

Mixed evidence

Limited evidence suggests boron status may influence aspects of brain electrical activity and cognitive performance, but the data are sparse.

Wound healing

Grade D

Mixed evidence

Topical boron compounds (boric acid) and oral boron have shown some benefit in wound healing studies, with limited high-quality clinical evidence in humans.

3 commercial forms

Boron glycinate (boron amino acid chelate)

Chelated form; well tolerated.

Common in supplement formulas. No clear evidence of superior bioavailability over other forms.

Boron citrate

Organic salt; well absorbed.

Frequently used in supplements; comparable to other forms.

Sodium borate (borax-derived)

Inorganic source; well absorbed but higher boron content per gram.

Less common in supplements; more often industrial.

Dosage

There is no RDA or AI for boron. Typical Western diets provide 0.5-3 mg/day. Most boron supplements provide 3-10 mg/day. The Tolerable Upper Intake Level (UL) is 20 mg/day for adults. Studies on bone health and hormones have typically used 3-10 mg/day.

When and how to take it

Boron can be taken at any time, with or without food. There is no established preferred timing. Most users take it with a meal to improve tolerance. For bone-support combinations, dosing alongside calcium and magnesium is convenient but not specifically required.

Food sources

FoodAmount%DV
Avocado (1 medium)2.1 mg—
Raisins (1.5 oz)1.0 mg—
Prunes (1.5 oz)0.9 mg—
Peanuts (1 oz)0.5 mg—
Apples (1 medium)0.3 mg—
Coffee (1 cup)0.1 mg—
Wine (5 oz)0.5 mg—
Beans, kidney (1 cup, cooked)1.0 mg—

Safety

Boron at supplemental doses up to 10 mg/day is generally well-tolerated. Higher intakes (above 20 mg/day) can cause nausea, vomiting, diarrhea, headache, and skin rash. Very high acute intake is associated with seizures and other neurological symptoms. Stay within the UL.

Who should be cautious

Pregnant women should avoid boron supplements above dietary levels because higher intakes have been linked to developmental effects in animal studies. People with hormone-sensitive cancers (breast, prostate, uterine, ovarian) should discuss with a clinician before supplementing. Avoid in kidney disease.

Interactions

Boron may influence estrogen levels, so caution with hormone therapy or hormone-sensitive conditions. May increase magnesium retention. Otherwise few documented drug interactions. Boron-containing pesticides or industrial exposures are unrelated to dietary supplements but contribute to total body burden.

Frequently asked questions

Is boron essential?⌄

It is considered conditionally essential or beneficial rather than formally essential. There is no established RDA, but emerging evidence supports a physiological role in bone and mineral metabolism.

Does boron raise testosterone?⌄

Some small short-term studies have shown modest increases in free testosterone with boron supplementation. Effects are not large enough to compare with hormone therapy, and long-term implications are unclear.

Can boron help with arthritis?⌄

Observational data and small trials suggest possible benefits for joint comfort, but evidence is preliminary. It is not a primary therapy for arthritis.

Is boron safe to take daily?⌄

Doses up to 10 mg/day are generally well-tolerated in healthy adults. Stay below the UL of 20 mg/day. Pregnant women should not supplement above dietary levels.

Why do bone-support products contain boron?⌄

Studies suggest boron influences calcium and magnesium retention and may interact with vitamin D and estrogen pathways, all of which support bone metabolism. The contribution is modest compared to calcium, vitamin D, and exercise.

References

  • NIH Office of Dietary Supplements - Boron Fact Sheet — NIH ODS link
  • Boron - Wikidata — Wikidata link

Track Boron with Pilora

Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.

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Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you're pregnant, breastfeeding, on medications, or managing a chronic condition.