Alpha-ketoglutarate (AKG), an endogenous intermediary metabolite in the Krebs cycle, is a molecule involved in multiple metabolic and cellular pathways. As an intermediate of the tricarboxylic acid cycle, AKG is essential for the oxidation of fatty acids, amino acids, and glucose. Extracellular AKG is a significant source of energy for cells of the gastrointestinal tract. As a precursor for the synthesis of glutamate and glutamine in multiple tissues (including liver, skeletal muscle, heart, brain, and white adipose tissue), AKG bridges carbohydrate and nitrogen metabolism for both conservation of amino acids and ammonia detoxification. Additionally, emerging evidence shows that AKG is a regulator of gene expression and cell signaling pathways (including the mammalian target of rapamycin and AMPactivated protein kinase). Thus, AKG is an attractive dietary supplement in animal and human nutrition to improve cellular energy status, immunity, and health.AKG can decrease protein catabolism and increase protein synthesis to enhance bone tissue formation in the skeletal muscles and can be used in clinical applications. In addition to these health benefits, a recent study has shown that AKG can extend the lifespan of adult Caenorhabditis elegans by inhibiting ATP synthase and TOR. Orally, AKG is used for kidney disease, gastrointestinal disorders, bacterial overgrowth, intestinal toxemia, liver dysfunction, and chronic candidiasis. It is also used for improving peak athletic performance, improving amino acid metabolism in hemodialysis patients, and cataracts. Intravenously, AKG is used for preventing ischemic injury during heart surgery, improving renal blood flow after heart surgery, and preventing muscle protein depletion after surgery or trauma.

Cholecalciferol (/ˌkoʊləkælˈsɪfərɒl/) (vitamin D3) is one of the five forms of vitamin D. Cholecalciferol is a steroid hormone that has long been known for its important role in regulating body levels of calcium and phosphorus, in mineralization of bone, and for the assimilation of Vitamin A. The classical manifestation of vitamin D deficiency is rickets, which is seen in children and results in bony deformities including bowed long bones. Most people meet at least some of their vitamin D needs through exposure to sunlight. Ultraviolet (UV) B radiation with a wavelength of 290–320 nanometers penetrates uncovered skin and converts cutaneous 7-dehydrocholesterol to previtamin D3, which in turn becomes vitamin D3. In supplements and fortified foods, vitamin D is available in two forms, D2 (ergocalciferol) and D3 (cholecalciferol) that differ chemically only in their side-chain structure. Vitamin D2 is manufactured by the UV irradiation of ergosterol in yeast, and vitamin D3 is manufactured by the irradiation of 7-dehydrocholesterol from lanolin and the chemical conversion of cholesterol. The two forms have traditionally been regarded as equivalent based on their ability to cure rickets and, indeed, most steps involved in the metabolism and actions of vitamin D2 and vitamin D3 are identical. Both forms (as well as vitamin D in foods and from cutaneous synthesis) effectively raise serum 25(OH) D levels. Firm conclusions about any different effects of these two forms of vitamin D cannot be drawn. However, it appears that at nutritional doses, vitamins D2 and D3 are equivalent, but at high doses, vitamin D2 is less potent. The American Academy of Pediatrics (AAP) recommends that exclusively and partially breastfed infants receive supplements of 400 IU/day of vitamin D shortly after birth and continue to receive these supplements until they are weaned and consume ≥1,000 mL/day of vitamin D-fortified formula or whole milk. Cholecalciferol is used in diet supplementary to treat Vitamin D Deficiency. Cholecalciferol is inactive: it is converted to its active form by two hydroxylations: the first in the liver, the second in the kidney, to form calcitriol, whose action is mediated by the vitamin D receptor, a nuclear receptor which regulates the synthesis of hundreds of enzymes and is present in virtually every cell in the body. Calcitriol increases the serum calcium concentrations by increasing GI absorption of phosphorus and calcium, increasing osteoclastic resorption, and increasing distal renal tubular reabsorption of calcium. Calcitriol appears to promote intestinal absorption of calcium through binding to the vitamin D receptor in the mucosal cytoplasm of the intestine. Subsequently, calcium is absorbed through formation of a calcium-binding protein.

Anhydrous dibasic calcium phosphate is a calcium salt of phosphoric acid. It is used as a diluent in pharmaceutical industry, in some toothpastes as a polishing agent. Calcium phosphate is generally recognized as safe by FDA. Dibasic calcium phosphate is ised as a supplement to treat conditions associated with calcium deficit, such as bone loss (osteoporosis), weak bones (osteomalacia/rickets), decreased activity of the parathyroid gland (hypoparathyroidism), and a certain muscle disease (latent tetany)

Lactose is the most important carbohydrate in the milk of most species. Its biosynthesis takes place in the mammary gland. The molecular structures of α- and β -lactose differ in the orientation of a hydrogen- and a hydroxyl group on carbon atom no.1 in the glucose moiety. Both forms change into one another continuously. At room temperature, the equilibrium results in a ratio of about 40% α-lactose and 60% β-lactose. The fact that two forms of lactose exist which differ in molecular structure has profound effects on various properties of lactose such as crystallization behavior, crystal morphology, solid-state properties, and solubility. The intestine does not actively absorb lactose unless it is split into its two-monosaccharide components, i.e. glucose and galactose. This hydrolysis of lactose is affected by the enzyme lactase, which is produced by the epithelium cells in the brush-border of the small intestine. Thus, the capacity of mammals to digest lactose is dependent on the lactase activity in the intestine. The maximum activity of the enzyme occurs shortly after birth and declines during the weaning period, after which it remains at a relatively constant level. Genetically determined factors governing residual lactase activity also exist. Individuals having low lactase activity are called lactose malabsorbers. Lactose intolerance is a condition in which people have symptoms due to the decreased ability to digest lactose. The principal symptom of lactose intolerance is an adverse reaction to products containing lactose (primarily milk), including abdominal bloating and cramps, flatulence, diarrhea, nausea, borborygmi, and vomiting (particularly in adolescents). These appear one-half to two hours after consumption.

Aconitic Acid found in leaves and tubers of Aconitum napellus L., Ranunculaceae, in various species of Achillea (Compositae) and Equisetum (Equisetaceae), in beet root, and in sugar cane. It is indicated for the temporary relief of symptoms of chronic illness including fatigue, effects of toxin buildup, slowed metabolism, weakened constitution. The limited data on trans-aconitic acid indicate it to be less toxic than citric acid. Trans-aconitate salts appear to be excreted readily by the kidneys. There is no direct evidence that trans-aconitic acid is utilized as is the cis-aconitic acid isomer in mammalian metabolism although non-specific oxidation probably occurs.

Maltose, a disaccharide, is found mainly in grains and cereals. Nutritionally, maltose provides the same number of calories as starches and other sugars. Maltose can be the agent responsible for the primary signals to induce the sensations of hunger and satiation in human beings. It was shown, that parenterally administered maltose could be of clinical value.