Barium biological function

The behavior of metals as atoms or ions deeply affects the electrochemical reactions they undergo, and similarly affects the metabolism of plants and animals. Iron, copper, cobalt, potassium, and sodium are examples of metals that are essential to biological function. Some metals such as cadmium, mercury, lead, barium, chromium, and beryllium are highly toxic. 

Until now, no definitive proof has been provided of the essential functions of barium in plants, animals or man, though some clues for the biological functions of barium do exist. In 1949, Rygh fed rats with a semisynthetic diet which was depleted of barium, strontium, and zinc in all possible variations. The feeding with barium-depleted rations was found to cause a reduced lifespan, and also reduced the animals increase in body weight. However, no other investigations into barium depletion have been published. 

Barium is a non essential element for humans, and has no biological role. It is an abundant element and humans take about 1 mg per day through foods (carrots, onions, lettuce and oranges). Barium is similar to calcium and is absorbed easily, but it does not have any known useful purpose and function in the body. 

Both strontium and barium are deposited as crystals in a range of organisms. These crystals may have both structural and functional properties. Some green algae such as the desmids deposit barium sulfate crystals, though it is unclear how much biological control is involved in the determination of the crystal structure which results [10]. 

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