Boron
What it does
Boron is a trace mineral most people never think about, partly because it has no official RDA or Daily Value. It is not a building-block mineral like calcium, but it appears to influence how the body handles minerals, vitamin D, and bone-related metabolism. That makes boron interesting: the question is not classic deficiency, but whether low plant-food intake leaves this quiet support mineral lower than expected.
Boron intake depends heavily on plant foods such as fruits, legumes, nuts, potatoes, and avocados, with soil and water content adding variability. No official recommended intake has been established; many U.S. adults get about 1 mg per day, while plant-rich diets tend to provide more. The ideal range shown here is 3 to 6 mg, and the upper limit is 20 mg.
Bone and mineral metabolism. Boron appears to support the way the body handles calcium, magnesium, and vitamin D, which is why it is often discussed in the context of bone health.
Vitamin D and hormone activity. Boron appears to influence vitamin D and steroid hormone metabolism. The observed effects concern how the body handles these compounds rather than raising hormone levels.
Inflammation and joint context. Boron has been studied for possible roles in joint comfort and inflammatory signaling. The evidence is still developing, and no joint-health benefit has been established well enough to treat boron as a treatment.
Plant-food pattern marker. Because many boron-rich foods are fruits, legumes, nuts, and avocados, low boron intake often tracks with diets that are low in plant foods overall.
Why boron can be inconsistent
Boron intake varies because it depends heavily on plant-food intake, soil content, and water content. People eating more fruits, legumes, nuts, potatoes, and avocados tend to get more boron than people eating few plant foods.
Plant foods drive intake. Fruits, legumes, tubers, nuts, and some beverages provide most dietary boron. Meat is generally low in boron, so diets built mostly around animal foods and refined grains may provide less.
Soil and water matter. Boron content varies by region because plants take up boron from soil and water. The same food can contain different amounts depending on where it was grown.
No label makes it easy to miss. Boron does not have a Daily Value, and most food databases do not list boron content. That makes it harder for consumers to notice compared with nutrients like calcium, magnesium, or vitamin D.
Who may need to pay closer attention
Some people are more likely to have inconsistent boron intake than others:
- people who eat few fruits, legumes, nuts, potatoes, or avocados
- people eating very low-plant-food diets
- people with low overall dietary variety
- people focused on bone-health nutrition who already track calcium, magnesium, vitamin D, and vitamin K
- people using boron supplements, since the adult upper limit is 20 mg per day
Because no requirement has been set for boron, none of these can be measured against a target. They describe how much the diet is likely supplying.
Best food sources
Boron appears primarily in plant foods, with particularly high amounts in fruits, legumes, nuts, and avocados.
| Food | Boron per serving |
|---|---|
| Prune juice (1 cup) | ~1.43 mg |
| Avocado, cubed (1/2 cup) | ~1.07 mg |
| Raisins (1.5 oz) | ~0.95 mg |
| Peach (1 medium) | ~0.80 mg |
| Grape juice (1 cup) | ~0.76 mg |
| Apple (1 medium) | ~0.66 mg |
| Pear (1 medium) | ~0.50 mg |
| Peanuts (1 oz) | ~0.48 mg |
| Refried beans (1/2 cup) | ~0.48 mg |
| Peanut butter (2 tbsp) | ~0.46 mg |
The plant-food pattern. Boron is not hard to find, but it is easy to miss if fruits, legumes, nuts, potatoes, and avocados are not part of the routine. A few boron-rich plant foods can raise intake meaningfully because normal daily intake is measured in milligrams, not hundreds of milligrams.
How much do you need?
No official RDA or AI
No official RDA, AI, EAR, or Daily Value has been established for boron. Typical U.S. adult intake is often around 1 mg per day, and people who eat more plant foods tend to get more boron.
Practical intake range
A range of roughly 3 to 6 mg per day from food and supplements combined is often cited in discussions of boron and bone health. No official body has endorsed it as a requirement, and it sits well below the adult upper limit.
Safe upper limit
The adult upper limit is 20 mg per day from all sources. This is much higher than typical food intake, but it matters for people using boron supplements or combining multiple products.
Forms and supplements
When boron appears in supplements, several forms are commonly used.
Boron citrate, glycinate, aspartate, and gluconate
These are common supplemental forms. Scientists do not know whether one form is better than the others for general boron coverage.
Calcium fructoborate
Calcium fructoborate is a boron-containing compound also found naturally in some plant foods. It appears in supplements studied for joint and bone outcomes. Whether it covers everyday boron needs better than the simpler forms has not been established.
Nutrient context
Calcium and magnesium
Boron appears to influence calcium and magnesium handling, which is one reason it is often discussed alongside bone-health minerals.
Vitamin D
Boron may affect vitamin D metabolism, which is part of why the two are discussed together in bone health. Boron does not supply vitamin D, and adequate boron does not reduce the need for it from food, supplements, or sunlight.
What to check in your routine
Boron has no requirement to check intake against, so the question is whether the diet includes the foods that carry it: fruit, legumes, nuts, potatoes, and avocados. Diets built mainly on meat and refined grains supply the least.
Typical intake sits near 1 mg and the upper limit is 20 mg, so there is a wide margin in either direction. That margin also means there is little basis for treating a boron supplement as filling a known shortfall.
See how boron shows up in your usual diet →
The information on this page is educational and does not constitute medical advice. Talk to a qualified healthcare provider before making changes to your supplement regimen or interpreting lab results.