boron

Boron is a trace mineral found in many foods, especially plant foods such as fruits, fruit juices, avocados, potatoes, nuts, and legumes. According to the NIH Office of Dietary Supplements, scientists have not identified a clear biological function for boron in the human body, so it is not classified as an essential nutrient, and no recommended intake (RDA, AI, or EAR) has been established. Most US adults get about 1 mg of boron per day from food.

Evidence for benefit in humans is limited and inconclusive. The NIH notes that boron might have beneficial effects on functions such as calcium metabolism, bone formation, brain function, and the activity of steroid hormones, but it repeatedly states that more research is needed to understand these effects. Some studies have looked at whether boron supports bone health or eases osteoarthritis symptoms, but human findings are mixed and have not established a clear effect on bone mineral density; boron is also not classified as an essential nutrient. Boron should not be assumed to prevent, treat, or cure any disease.

No recommended intake has been set, because boron is not considered an essential nutrient, and most people already get about 1 mg per day from food. Supplements supply boron in many forms (such as boron citrate, glycinate, aspartate, or calcium fructoborate), with common amounts of elemental boron ranging from roughly 0.15 to 6 mg. The NIH lists a daily upper limit for adults (ages 19 and older) of 20 mg from all sources combined; talk to a clinician or pharmacist before starting boron, especially if you are pregnant, breastfeeding, or have a health condition.

According to the NIH, boron in foods and beverages is not harmful at typical dietary levels. To stay within safe limits, total intake from food, beverages, and supplements should remain at or below the daily upper limit (20 mg/day for adults). Serious harm can occur if a person accidentally swallows cleaning products or pesticides that contain certain forms of boron, such as borax (sodium borate) or boric acid, which are not meant to be eaten.

Boron is generally well tolerated at the small amounts found in food and typical supplements. The NIH states that symptoms of too much boron include nausea, vomiting, diarrhea, rashes (skin reactions), headaches, and convulsions, and that very high amounts of boron can cause death. These effects are linked to excessive intake well above normal dietary or supplemental levels.

The NIH Office of Dietary Supplements reports that boron is not known to interact or interfere with any medicines or other dietary supplements. Even so, it is wise to tell your doctor and pharmacist about every supplement and medicine you take, so they can check for any concerns specific to your situation.