Strontium is a soft, silver-yellow, alkaline-earth metal, existing either in the elemental state or as the divalent ion. Strontium occurs naturally in the earth's mantle as a mixture of four stable isotopes, i.e. Sr-84, Sr-86, Sr-87, and Sr-88. Of these, Sr-88 is the most prevalent form, comprising about 83% of natural strontium. Natural stable strontium is abundant in the environment and can be found in all plant species. Consuming 75% of production, the primary use for strontium is in glass for color television cathode ray tubes, where it prevents X-ray emission. Acantharea, a relatively large group of marine radiolarian protozoa, produce intricate mineral skeletons composed of strontium sulfate. In biological systems, calcium is substituted in a small extent by strontium. In the human body, most of the absorbed strontium is deposited in the bones. The ratio of strontium to calcium in human bones is between 1:1000 and 1:2000, roughly in the same range as in the blood serum. The human body absorbs strontium as if it were its lighter congener calcium. Because the elements are chemically very similar, stable strontium isotopes do not pose a significant health threat. The average human has an intake of about two milligrams of strontium a day.

Phosphorus P-32 (P-32) is the phosphorus isotope whose nucleus consists of 15 protons and 17 neutrons. Phosphorus P-32 is one of the most commonly used research emitters and is the one with the highest energy. Its use in molecular biology has become widespread by the use of specific high-activity nucleotides to mark DNA. Phosphorus P-32 may also be used in phosphorylation reactions. More precisely, it is used in the study of the migration of fertilizers (phosphates) in soils. In the medical field, phosphorus P-32 has been used for the treatment of polyglobulia, but this is increasingly rare. Emitted by phosphorus P-32, beta particles directly damage cellular DNA and, by ionizing intracellular water to produce several types of cytotoxic free radicals and superoxides, indirectly damage intracellular biological macromolecules, resulting in tumor cell death.

Barium is a soft, silvery metal that rapidly tarnishes in air and reacts with water. Barium is not an extensively used element. Most is used in drilling fluids for oil and gas wells. It is also used in paint and in glassmaking. All barium compounds are toxic; however, barium sulfate is insoluble and so can be safely swallowed. A suspension of barium sulfate is sometimes given to patients suffering from digestive disorders. This is a ‘barium meal’ or ‘barium enema’. Barium is a heavy element and scatters X-rays, so as it passes through the body the stomach and intestines can be distinguished on an X-ray. Barium carbonate has been used in the past as a rat poison. Barium nitrate gives fireworks a green colour. Barium has no known biological role, although barium sulfate has been found in one particular type of algae. Barium is toxic, as are its water- or acid-soluble compounds. This drug is used as a contrast agent in diagnostic x-ray procedures. Therapeutic advantages of barium sulfate in diagnostic procedures include both its low water solubility and high level of clearance from the body. Barium sulfate is ingested by mouth or administered rectally and combined with granules of effervescent bicarbonate to enhance distension of the GI tract, allowing for enhanced gastrointestinal tract visualization. Barium (E-Z-CAT DRY) is a radiographic contrast agent indicated for use in computed tomography (CT) of the abdomen to delineate the gastrointestinal (GI) tract in adult and pediatric patients. Under physiological conditions, barium sulfate passes through the GI tract in an unchanged form and is absorbed only in pharmacologically insignificant amounts. Common adverse reactions include nausea, vomiting, diarrhea and abdominal cramping.

LANTHANUM belongs to the rare earth metals being a prototypical element of this group. Its compounds have numerous industrial applications as catalysts, glass additives, electron cathodes, scintillators, and others. Also, it can be used as a feed additive to improve animal health and production.

Boron gluconate is a boron-containing dietary supplement. Calcium salt of boron gluconate is used as a calcium supplement in veterinary to treat hypocalcemia (also called parturient paresis and commonly called milk fever) in cattle, sheep, and goat.

Silver is a soft metal that is used medically in surgical instruments, dental prostheses, and alloys. According to FDA final rule, all over-the-counter drug products containing colloidal silver ingredients or silver salts for internal or external use are not generally recognized as safe and effective and are misbranded.

Gold chloride (AUCl3), dihydrate, also called gold trichloride or auric chlorise, is a compound comprised of gold and chloride. It exists as a chloride-bridged dimer, both as a solid and as a vapor. AUCl3 is very hygroscopic and highly soluble in water and ethanol. It is used in organic chemistry as a mild acid catalyst and as a alternative to mercury salts. It is known to cause allergic reactions in subjects with known gold allergy.

Chromium is a metallic element (atomic number: 24, atomic mass: 51.99), it is a mineral essential in the action of insulin and is present in very small quantities in many enzymes. Chromium is also present in many foods such as brewers' yeast, seeds, peanuts, wheat germ and skimmed milk. Chromium Cr-51 is an isotope of chromium that is observationally stable. When intravenously administered, it is used as a diagnostic radiopharmaceutical agent to determine the red blood cell volume or mass, study the red blood cell survival time and evaluate blood loss. Chromium 51 is also used for labeling platelets, and for the diagnosis of gastrointestinal bleeding.

Molybdenum Hexachloride is an inorganic diamagnetic compound used for catalytic polymerization of cycloolefins.

Selenium (Se) is mineral that is found in soil and occurs naturally in certain foods (such as whole grains, Brazil nuts, sunflower seeds, and seafood). Selenium, which is nutritionally essential for humans, is a constituent of more than two dozen selenoproteins that play critical roles in reproduction, thyroid hormone metabolism, DNA synthesis, and protection from oxidative damage and infection. Selenium is used to treat or prevent selenium deficiency. Selenium deficiency produces biochemical changes that might predispose people who experience additional stresses to develop certain illnesses. For example, selenium deficiency in combination with a second stress (possibly a viral infection) leads to Keshan disease, a cardiomyopathy that occurred in parts of China prior to a government-sponsored selenium supplementation program that began in the 1970s. Before the Chinese government supplementation program, adults in the Keshan disease areas had average selenium intakes of no more than 11 mcg/day; intakes of at least 20 mcg/day protect adults from Keshan disease. Selenium has been used in alternative medicine as an aid to treat Hashimoto's thyroiditis, and to treat high cholesterol. Selenium is an important enzyme in the prevention of cellular damage by free radicals and reactive oxygen species. Selenium is first metabolized to selenophosphate and selenocysteine. Selenium incorporation is genetically encoded through the RNA sequence UGA. This sequence is recognized by RNA ste loop structures called selenocysteine inserting sequences (SECIS). These structures require the binding of SECIS binding proteins (SBP-2) to recognize selenocystiene. The specialized tRNA is first bound to a serine residue which is then enzymatically processed to a selylcysteyl-tRNA by selenocystiene sythase using selenophosphate as a selenium donor. Other unidentified proteins are required as part of the binding of this tRNA to the ribosome. Numerous studies in animal models and more recent studies in humans have demonstrated cancer chemopreventive effects with Se. There is extensive evidence that monomethylated forms of Se are critical metabolites for chemopreventive effects of Se. Induction of apoptosis in transformed cells is an important chemopreventive mechanism. Apoptosis can be triggered by micromolar levels of monomethylated forms of Se independent of DNA damage and in cells having a null p53 phenotype. Cell cycle protein kinase cdk2 and protein kinase C are strongly inhibited by various forms of Se. Inhibitory mechanisms involving modification of cysteine residues in proteins by Se have been proposed that involve formation of Se adducts of the selenotrisulfide (S-Se-S) or selenenylsulfide (S-Se) type or catalysis of disulfide formation. Selenium may facilitate reactions of protein cysteine residues by the transient formation of more reactive S-Se intermediates. A novel chemopreventive mechanism is proposed involving Se catalysis of reversible cysteine/disulfide transformations that occur in a number of redox-regulated proteins, including transcription factors. A time-limited activation mechanism for such proteins, with deactivation facilitated by Se, would allow normalization of critical cellular processes in the early stages of transformation. Randomized controlled trials of selenium supplementation for cancer prevention have yielded conflicting results. In 2003, the FDA allowed a qualified health claim on foods and dietary supplements containing selenium to state that while “some scientific evidence suggests that consumption of selenium may reduce the risk of certain forms of cancer… FDA has determined that this evidence is limited and not conclusive”. Selenium is available in multivitamin/multimineral supplements and as a stand-alone supplement, often in the forms of selenomethionine or of selenium-enriched yeast (grown in a high-selenium medium) or as sodium selenite or sodium selenate.