Boron is a trace mineral naturally present in many foods and the environment. While not officially classified as an essential nutrient by all regulatory bodies, research suggests it plays several significant roles within the human body. A varied diet is the primary source for this compound, as the average person’s daily intake is relatively low. Understanding how to obtain this mineral and the associated safety guidelines is important for optimizing nutrient intake.
The Role of Boron in Human Health
Boron supports skeletal integrity by influencing the metabolism of calcium and magnesium, two compounds fundamental to bone structure. Adequate boron intake helps reduce the amount of calcium and magnesium excreted through urine, supporting their retention in the body for bone health.
The mineral also plays a part in modulating steroid hormones, specifically affecting the concentration of sex hormones like estrogen and testosterone. This influence is particularly relevant for postmenopausal women, where supplementation has been observed to help maintain serum estrogen levels.
Boron is also linked to supporting cognitive function and processing. Low intake has been associated with reduced mental alertness and impaired executive brain functions. Performance in tasks requiring hand-eye coordination, attention, and short-term memory may suffer when boron levels are insufficient.
Acquiring Boron Through Diet
The most straightforward way to acquire boron is by consuming a diverse diet rich in plant-based foods, such as fruits, vegetables, nuts, and legumes. Because boron is essential for plant growth, these foods absorb it from the soil, making them reliable dietary sources.
The mineral content of plant foods is heavily influenced by the soil quality in which they are grown. Soil in arid regions often retains more boron, leading to higher concentrations in harvested crops. Conversely, areas with high rainfall experience leaching, which washes the mineral out of the soil and can result in lower boron levels in local produce.
Fruits, particularly dried varieties such as raisins, prunes, and apricots, are excellent sources due to the concentration that occurs during the drying process. Other strong contributors to dietary boron intake include apples, avocados, potatoes, and peanuts. Certain beverages also contain notable amounts, with wine and cider being better sources than beer or coffee.
Since the mineral is widely distributed in the plant kingdom, maintaining a consistently varied eating pattern is the most effective approach for dietary acquisition. Adults in the United States typically consume between 1 and 1.5 milligrams of boron per day from food sources alone.
Supplementation Guidelines and Safety
Since the exact biological function of boron has not been conclusively identified, there is no official Recommended Dietary Allowance (RDA) established. However, a daily intake of 3 milligrams is often cited as the lowest level at which beneficial effects, particularly on hormonal parameters, have been observed in studies.
Boron supplements often come as chelates or compounds designed to enhance absorption. Common supplemental forms include:
- Boron citrate
- Boron glycinate
- Boron aspartate
- Calcium fructoborate
When selecting a supplement, note that the dosage listed represents the amount of elemental boron, not the weight of the entire compound.
The established Tolerable Upper Intake Level (UL) for adults is 20 milligrams per day from all sources, including food and supplements. This UL is based on preventing reproductive and developmental issues observed in animal studies. Supplementation may be considered for those with very low dietary intake or specific bone or joint health goals, but it must remain below this upper limit.
Consuming excessively high amounts of boron can lead to acute toxicity, though this is rare from food sources alone. Symptoms of acute toxicity, typically associated with accidental consumption of compounds like boric acid or borax, include nausea, vomiting, diarrhea, and abdominal pain. More severe cases can cause skin flushing, headache, and tremors.