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THYROID FUNCTION

Boron

B — Element #5

also known as Boric acid, Borax, Calcium fructoborate, Boron citrate

Boron is an ultratrace mineral found in fruits, vegetables, legumes, and nuts. While no RDA has been established, boron appears to influence steroid hormone metabolism, bone mineral density, and brain function. Animal studies demonstrate it is essential for normal bone development and reproduction, and it may modulate the metabolism of vitamin D, estrogen, and testosterone.

May augment or mimic estrogen and testosterone effects, potentially supporting bone mineral density in postmenopausal women
Animal studies suggest boron is required for normal bone formation and is synergistic with vitamin D in calcium metabolism
Associated with improved cognitive performance (attention, memory) in observational studies
May reduce inflammatory markers (CRP, TNF-α) at doses of 3–6 mg/day in some trials
Plays a role in modulating the use of energy substrates (carbohydrate, fat) in cell membranes

Active in B(OH)₃ (boric acid), B(OH)₄⁻ (borate).

Tolerable Upper Intake Level (UL): 20 mg/day for adults

High doses (above UL) can cause nausea, vomiting, diarrhea, skin rash, and in severe cases kidney damage

Boron has estrogenic activity and should be used cautiously by individuals with hormone-sensitive conditions (e.g., breast, uterine, or ovarian cancer)

Evidence supporting boron supplementation for specific health outcomes in humans is preliminary and insufficient to establish an RDA

NIH ODS — Boron · NCBI — Boron and Human Health · Britannica — Boron

Works with

Calcium Boron reduces urinary calcium excretion and is associated with improved bone mineral density in osteoporosis prevention protocols.

Enhances

Vitamin D Boron has been shown to increase serum 25-hydroxyvitamin D and reduce urinary calcium and magnesium losses.

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