Boron shows up in a wide range of foods, drinks, and everyday household products. In your diet, the richest sources are plant-based: fruits, nuts, legumes, and vegetables consistently deliver the most boron per serving. Most people get between 1 and 3 mg of boron per day from food alone, though the exact amount depends heavily on how much produce you eat.
Fruits With the Most Boron
Fruits are among the top dietary sources of boron. Prunes, raisins, and dried apricots are especially concentrated because removing water packs the mineral into a smaller serving size. A handful of prunes (about 100 grams) can deliver over 1 mg of boron. Fresh fruits like avocados, apples, pears, grapes, and peaches also contribute meaningful amounts, though less per bite than their dried counterparts.
Citrus fruits, bananas, and cherries round out the list. If you eat several servings of fruit per day, fruit alone can account for a large portion of your total boron intake.
Nuts, Legumes, and Other Plant Foods
After fruit, nuts and legumes are the next biggest contributors. Almonds, hazelnuts, walnuts, and peanut butter all contain notable amounts of boron. A single ounce of almonds provides roughly 0.4 mg. Peanuts and pecans are in a similar range.
Among legumes, red kidney beans, chickpeas, and lentils are reliable sources. Soybeans and soy-based foods also tend to be boron-rich. Vegetables like broccoli, leafy greens, and potatoes contribute smaller but consistent amounts, especially if you eat them regularly.
Wine, coffee, and milk also contain trace amounts. Red wine, in particular, carries boron from the grapes it’s made from.
Boron in Drinking Water
Your tap water contains boron too, though the amount varies depending on where you live. According to the World Health Organization, boron concentrations in drinking water around the world typically fall between 0.1 and 0.3 mg per liter. In some regions, levels run as high as 15 mg per liter, though that’s uncommon. For most people, water is a minor source compared to food.
Why Boron Content Varies by Region
The boron in your produce depends on the boron in the soil where it was grown, and soil levels vary dramatically by geography. Organic matter in soil is the primary reservoir of boron. As that organic matter decomposes, boron becomes available for plants to absorb. Sandy, low-organic-matter soils tend to have less boron because it leaches away easily. Drought also reduces boron availability: the mineral travels to plant roots through soil moisture, so dry conditions slow that process down. After rainfall, boron concentrations in plant tissue often spike as moisture releases the mineral from the soil.
This means two apples grown in different parts of the country can have meaningfully different boron levels. There’s no practical way to know the exact boron content of a specific piece of fruit, but eating a variety of plant foods from different sources helps balance out any regional gaps.
Household Products That Contain Boron
Outside the kitchen, boron compounds appear in a surprising number of everyday items. Borax (sodium tetraborate) is the most common form and serves as a versatile ingredient across industries:
- Cleaning products: Borax is a staple in laundry boosters, all-purpose cleaners, and diaper presoak products, where it helps neutralize odors and lift stains.
- Cosmetics: Small amounts of borax appear in some skincare and makeup formulations as a buffering agent or emulsifier.
- Glass and ceramics: Boron compounds are a key ingredient in heat-resistant glass (like Pyrex), fiberglass insulation, and porcelain glazes.
- Flame retardants: Boron-based compounds are added to building materials and textiles to slow the spread of fire.
- Contact lens solution: Many lens solutions contain borax or boric acid as a buffering agent, even some marketed as “borax-free” alternatives for DIY slime recipes.
What Boron Does in Your Body
Boron isn’t classified as an essential nutrient because scientists haven’t pinpointed a single biological function it’s required for. But research suggests it plays a supporting role in several important processes. It appears to influence how your body handles calcium and magnesium, two minerals critical for bone strength. It also seems to affect levels of steroid hormones, including estrogen and vitamin D.
When boron intake drops low (around 0.25 mg per day in a 2,000-calorie diet), studies have observed increased loss of calcium and magnesium through urine, lower estrogen levels in postmenopausal women, and reduced vitamin D levels in both men and women. These shifts could, over time, affect bone mineral density. A diet that includes plenty of fruits, vegetables, and nuts typically provides enough boron to avoid these effects without any need for supplements.
How Much Boron Is Too Much
The tolerable upper intake level for adults is 20 mg per day. Reaching that threshold from food alone is virtually impossible. Most people consume well under 5 mg daily. The risk of excess comes almost entirely from supplements or accidental ingestion of boron-containing cleaning products. Symptoms of boron toxicity include nausea, vomiting, and diarrhea, with high doses potentially affecting the kidneys and liver.
If you eat a varied diet with regular servings of fruit, nuts, and vegetables, you’re almost certainly getting enough boron without thinking about it. The people most likely to fall short are those who eat very few plant foods overall.