top of page
July 2013



What is it?

Boron is an essential ultratrace element present in many foods although its exact role in human and animal physiology is not well understood.  Boron, in the form of borax (sodium borate) or boric acid, has good antiseptic, antifungal and antiviral properties. 


What does it do?

According to Dr Alexander Schauss, FACN, boron is one of the most important minerals involved in bone and joint health, likely as important as calcium and vitamin D.  Furthermore, boron can increase mental alertness, reduce inflammation and help in the metabolism of key hormones. Inadequate boron intake is involved in inflammatory processes such as joint swelling and osteoarthritis. 


Biochemist Walter Last explains that boron is essential for healthy bone and joint function as it regulates the absorption and metabolism of calcium, magnesium and phosphorus via its influence on the parathyroid glands.   Boron is for the parathyroids what iodine is for the thyroid. 


Boron deficiency causes the parathyroids to become overactive, releasing too much parathyroid hormone, which raises the blood level of calcium by releasing calcium from bones and teeth.  This then leads to osteoarthritis and other forms of arthritis, osteoporosis and tooth decay.  High blood levels of calcium can eventually lead to calcification of soft tissues causing muscle contractions and stiffness; calcification of endocrine glands, especially the pineal gland and the ovaries; arteriosclerosis, kidney stones, and calcification of the kidneys ultimately leading to kidney failure.  Boron deficiency combined with magnesium deficiency is especially damaging to the bones and teeth.

To read the article by Dr Alexander Schauss


To read the article by Walter Last

Why feed it to horses?

As boron deficiency causes greatly increased amounts of calcium and magnesium to be lost with the urine, supplemental boron intake may improve magnesium absorption and therefore may reduce the amount of magnesium needed by some horses.  Researcher George Eby reports that magnesium and calcium uptake can be increased by as much as one third when dietary boron is adequate.  Numerous horse owners have reported positive results within a few weeks of commencing boron supplementation.

Is it safe?

Boron is rapidly absorbed and then excreted; many reference sources, including Alexander Schauss and Walter Last, indicate that boron is non-toxic, similar to common table salt.  (F. H. Nielsen, PhD, Plant and Soil, June 1997, vol. 193, Issue 1-2, pp 199-208 Boron in human and animal nutrition).


However, as with all other minerals, horses with known or suspected kidney problems should not be given supplemental boron without a veterinarian’s supervision as impaired kidney function can reduce mineral excretion, causing excess minerals to accumulate within the body.



Where can it be purchased?

Boron, in the form of borax, can generally be found in the laundry and cleaning sections of some supermarkets.   Walter Last indicates there is no ‘food-grade’ borax available or necessary; the label usually states that it is 99% pure, which is considered safe to use for human consumption.

How much do horses need?

Veterinarian Dr J Mullholland recommends feeding about 4g to 5g of borax once per week for each horse as part of an anti-laminitis strategy ( Borax contains 11.3% boron, therefore 4g borax provides 452mg boron.


The following suggestion is based on using the lower recommendation, 4g, as a guide, but spread evenly over seven days to optimize magnesium absorption, rather than just once per week, as boron is rapidly absorbed and then excreted in urine. 


  1. Dissolve 20g borax powder (one rounded tablespoon) in one litre of hot water; this will contain 2,260mg of boron.

  2. Give each horse 30ml per day, preferably split over two feeds. This will provide each horse with about 67mg boron per day or 474mg per week.

Recommended reading:



William A. Albrecht, Ph.D

Any queries that arise after reading everything on this site can be directed to:

bottom of page