Boron

Overview

Boron is a trace mineral that has been recognized as an essential nutrient for plants for more than fifty years, but its essentiality in humans was not discovered until the mid-1980s. Since boron is a newly discovered essential nutrient for humans, some of the information about its metabolic activity and function is somewhat speculative. Research in the past decade, however, strongly implicates that boron plays roles in metabolism and bone health. The highest concentration of boron in humans is found in bones and dental enamel.

Dosage Info

Dosage Range

Dosages that have been used in clinical studies range from

Most Common Dosage

3mg daily.

Dosage Forms

Tablets and capsules.

Adult RDI

None established

Adult ODA

None established

RDA

  • None established:

Active Forms

Sodium borate and boron chelates, which include boron citrate, aspartate, and glycinate.

Absorption

Although boron is apparently well absorbed, very little is known about the actual mechanism of its absorption.

Toxicities & Precautions

General

No serious health or medical problems associated with its use have been reported in areas of the world where the daily diet supplies have been estimated up to 41mg/day of boron. (1)

Side Effects

Numerous case studies of poisonings and accidental ingestion seem to indicate a low toxicity for both boric acid and borax even at very high doses. The potential lethal dose for adults is estimated to be between 15 and 20 grams/day. (2) In a reported case of suicide, lethal ingestion of boric acid has occurred with the initial signs of toxicity being nausea, vomiting and diarrhea. (3)

Functions in the Body

Osteoporosis

Boron is one of the minerals that is necessary for the development of healthy bone tissue, and it apparently plays a role in the prevention of osteoporosis.

Magnesium Metabolism

Plays an important role in the metabolism of magnesium.

Hormone Production

Has a regulatory effect on the production of estrogens and testosterone. Biochemically, facilitates hydroxylation reactions, the addition of OH groups in chemical processes. The synthesis of estrogens and testosterone both require hydroxylation steps, so there is strong indication that boron influences production of these hormones.

Calcium Absorption

Helps convert vitamin D to its more active form, which means it indirectly facilitates in the absorption of calcium and the prevention of bone loss.

Clinical Applications

Osteoarthritis

A significant number of patients improve with boron supplementation (4) and studies show that there is an inverse relationship between intake of boron and the incidence of arthritis. (5) In areas of the world where soil levels are low and boron intake is 1.0 mg or less/day, the estimated incidence of arthritis ranges from 20 to 70%. However, in areas of the world where boron intakes are usually 3 to 10 mg/day, the estimated incidence of arthritis ranges from 0 to 10%. (6)

Osteoporosis

It has been suggested that boron is a trace mineral essential for skeletal health, and that it interacts metabolically with other nutrients that are important to bones such as calcium, magnesium, and vitamin D. (7) Animal and human studies have noted that boron deprivation alters calcium metabolism adversely affecting bone formation and maintenance. These effects are compounded in the presence of low dietary magnesium. In addition, boron supplementation has been shown to reduce urinary calcium excretion in postmenopausal women especially in populations with low dietary magnesium (44 percent reduction). (8) One literature review concluded that boron and magnesium supplementation are "apparently" necessary to prevent excessive bone loss common in postmenopausal women and older men. (9)

Rheumatoid Arthritis

Many patients, especially those with juvenile arthritis, respond with 6-9mg daily. (10)

Symptoms and Causes of Deficiency

Boron deficiency is rare. However, recent research indicates that boron deficiency may cause problems associated with arthritis and osteoporosis.

Dietary Sources

Several studies evaluating dietary boron intake have listed various foods that have higher boron content than other foods. The list includes: apples, avocados, chocolate, coffee, dried beans, grape juice, milk, peanut butter, peanuts, pecans, potatoes, prune juice, raisin granola/bran cereals and wine. (11)

References

  1. View Abstract: Naghii MR, Samman S. The role of boron in nutrition and metabolism. Prog Food Nutr Sci. Oct1993;17(4):331-49.
  2. Panel on Micronutrients, Subcommittees on Upper Reference Levels of Nutrients and of Interpretation and Use of Dietary Reference Intakes, and the Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food and Nutrition Board. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc; Washington, DC: National Academy Press; 2001:404-12.
  3. View Abstract: Restuccio A, Mortensen ME, Kelley MT. Fatal ingestion of boric acid in an adult. Am J Emerg Med. Nov1992;10(6):545-7.
  4. Travers RL, et al. Boron and Arthritis: The Results of a Double-blind Study. J Nutr Med. 1990;1:127-32.
  5. View Abstract: Newnham RE. Essentiality of boron for healthy bones and joints. Environ Health Perspect. Nov1994;102(Suppl 7):83-5.
  6. View Abstract: Newnham RE. Essentiality of Boron for Healthy Bones and Joints. Environ Health Perspect. Nov1994; 102(Suppl 7):83-85.
  7. View Abstract: Volpe SL, et al. The Relationship Between Boron and Magnesium Status and Bone Mineral Density in the Human: A Review. Magnes Res. Sep1993;6(3):291-96.
  8. View Abstract: Nielsen FH, et al. Effect of Dietary Boron on Mineral, Estrogen, and Testosterone Metabolism in Postmenopausal Women. Fed Am Soc Exp Biol. 1987;1(15):394-97.
  9. View Abstract: Nielsen FH. Studies on the relationship between boron and magnesium which possibly affects the formation and maintenance of bones. Magnes Trace Elem. 1990;9(2):61-9.
  10. Newnham RE. Arthritis or Skeletal Fluorosis and Boron. Int Clin Nutr Rev. 1991;11(2):68-70.
  11. Panel on Micronutrients, Subcommittees on Upper Reference Levels of Nutrients and of Interpretation and Use of Dietary Reference Intakes, and the Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food and Nutrition Board. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc; Washington, DC: National Academy Press; 2001:404-12.