Boron
Also known as: B
What Does Boron Measure?
Boron is a trace mineral measured in blood serum or plasma, reflecting the body's recent dietary intake and tissue levels of this element. Blood boron concentrations typically range in the micrograms per liter range and are measured using specialized techniques such as inductively coupled plasma mass spectrometry (ICP-MS). Because boron is not stored in significant quantities in soft tissues and is rapidly excreted through urine, serum boron levels closely mirror short-term dietary exposure rather than long-term body stores.
Why Does Boron Matter?
Although boron is not yet classified as an essential nutrient for humans, growing research suggests it plays important roles in bone health, brain function, hormone regulation, and inflammatory response. Boron appears to influence the metabolism of calcium, magnesium, and vitamin D — all critical for skeletal integrity. It may also modulate the activity of sex hormones such as estrogen and testosterone, support cognitive performance, and exhibit anti-inflammatory properties. Monitoring boron levels can be useful in functional medicine contexts, particularly for individuals with bone density concerns, hormonal imbalances, or diets very low in fruits and vegetables.
Normal Ranges
Males
20–100 µg/L (micrograms per liter) in serum
Females
20–100 µg/L (micrograms per liter) in serum
Children
Varies by age; generally lower than adults due to lower dietary intake; reference ranges not well established
Causes of High Levels
- High dietary intake of boron-rich foods (fruits, vegetables, legumes, nuts)
- Boron supplement use or boron-containing herbal products
- Occupational or environmental exposure to boron compounds (e.g., borax, boric acid)
- Impaired kidney function reducing boron excretion
- Use of boric acid-based medications or topical products with systemic absorption
Causes of Low Levels
- Low dietary intake of fruits, vegetables, and legumes (common in highly processed diets)
- Malabsorption syndromes such as Crohn's disease or celiac disease
- Strict elimination or restrictive diets lacking plant-based foods
- Excessive alcohol consumption interfering with mineral absorption
How to Improve Your Boron
Diet
- Increase intake of boron-rich foods such as prunes, raisins, dried apricots, and avocados
- Eat more almonds, walnuts, and peanuts, which are among the richest nut sources of boron
- Consume legumes regularly including chickpeas, lentils, and kidney beans
- Add leafy greens and broccoli to daily meals to boost overall boron intake
- Incorporate apples, grapes, and pears into your diet as commonly eaten fruits high in boron
Supplements
- Boron glycinate or boron citrate supplements: 3–6 mg per day is a commonly studied and well-tolerated dose
- Calcium fructoborate (a naturally occurring boron complex): 6–12 mg per day studied for joint and bone health
- A comprehensive trace mineral supplement containing boron if overall mineral status is low
- Consult a healthcare provider before supplementing, especially with doses above 10 mg/day due to potential toxicity
Related Biomarkers
Frequently Asked Questions
Is boron an essential nutrient that I need to track?
Boron has not been officially classified as an essential nutrient for humans, meaning no Recommended Daily Allowance (RDA) has been established. However, research suggests it has beneficial roles in bone health, hormone regulation, and brain function. Most health authorities consider adequate intake to be around 1–13 mg per day from food. Blood testing for boron is not routinely ordered but may be useful in functional or integrative medicine evaluations.
What are the symptoms of boron deficiency?
There is no well-defined clinical deficiency syndrome for boron in humans. However, low boron intake has been associated with reduced bone density, impaired cognitive function (particularly attention and memory), altered hormone levels (particularly lower estrogen and testosterone activity), and increased inflammation. People eating diets very low in fruits and vegetables are most at risk for suboptimal boron intake.
Can too much boron be harmful?
Yes, boron can be toxic at high doses. The Tolerable Upper Intake Level (UL) set by the National Academies is 20 mg per day for adults. Acute toxicity from excessive supplementation or accidental ingestion of boric acid can cause nausea, vomiting, diarrhea, skin rash, and in severe cases, kidney damage or neurological symptoms. This level of toxicity is very unlikely from food alone but can occur with high-dose supplements or industrial exposure.
Does boron help with testosterone levels?
Preliminary research suggests that boron supplementation may modestly increase free testosterone levels, particularly in men with low dietary boron intake. A notable study found that 10 mg of boron per day for one week increased free testosterone and decreased sex hormone-binding globulin (SHBG). However, the evidence is still limited and boron should not be considered a primary treatment for low testosterone. Speak with your doctor about comprehensive hormone evaluation before supplementing.