Doxercalciferol is a synthetic vitamin D2 analog that undergoes metabolic activation in vivo to form 1α,25-dihydroxyvitamin D2 (1α,25-(OH)2D2), a naturally occurring, biologically active form of vitamin D2. Doxercalciferol is indicated for the treatment of secondary hyperparathyroidism in patients with chronic kidney disease on dialysis, as well as for the treatment of secondary hyperparathyroidism in patients with Stage 3 or Stage 4 chronic kidney disease. Doxercalciferol is marketed under the brand name Hectorol by Genzyme Corporation, and is manufactured by Catalent Pharma Solutions, Inc.

Paricalcitol (Zemplar) is a synthetic vitamin D(2) analogue that inhibits the secretion of parathyroid hormone (PTH) through binding to the vitamin D receptor. It is approved in the US and in most European nations for intravenous use in the prevention and treatment of secondary hyperparathyroidism associated with chronic renal failure in adult, and in the US paediatric, patients. Paricalcitol effectively reduced elevated serum PTH levels and was generally well tolerated in children and adults with secondary hyperparathyroidism associated with chronic renal failure. In well designed clinical trials, paricalcitol was as effective as calcitriol and as well tolerated in terms of the incidence of prolonged hypercalcaemia and/or elevated calcium-phosphorus product (Ca x P). Preclinical and in vitro studies have demonstrated that paricalcitol's biological actions are mediated through binding of the vitamin D receptor, which results in the selective activation of vitamin D responsive pathways. Vitamin D and paricalcitol have been shown to reduce parathyroid hormone levels by inhibiting PTH synthesis and secretion.

Calcifediol (25-Hydroxyvitamin D3 or 25-hydroxycholecalciferol) is a biologically active vitamin D3 metabolite. It is concluded that the liver is the major if not the only physiologic site of hydroxylation of vitamin D3 into calcifediol. Calcifediol is a prohormone of the active form of vitamin D3, calcitriol (1,25-dihydroxyvitamin D3). Calcifediol is converted to calcitriol by cytochrome P450 27B1 (CYP27B1), also called 1-alpha hydroxylase, primarily in the kidney. Calcitriol binds to the vitamin D receptor in target tissues and activates vitamin D responsive pathways that result in increased intestinal absorption of calcium and phosphorus and reduced parathyroid hormone synthesis. RAYALDEE (calcifediol) extended-release capsules is indicated for the treatment of secondary hyperparathyroidism in adult patients with stage 3 or 4 chronic kidney disease.

Calcitriol is vitamin D3. Vitamin D is important for the absorption of calcium from the stomach and for the functioning of calcium in the body. Calcitriol is used to treat hyperparathyroidism (overactive parathyroid glands) and metabolic bone disease in people who have chronic kidney failure and are not receiving dialysis. Calcitriol is also used to treat calcium deficiency (hypocalcemia). The early signs and symptoms of vitamin D intoxication associated with hypercalcemia include: weakness, headache, somnolence, nausea, vomiting, dry mouth, constipation, muscle pain, bone pain and metallic taste. Cholestyramine has been reported to reduce intestinal absorption of fatsoluble vitamins; as such it may impair intestinal absorption of Calcitriol. Ketoconazole may inhibit both synthetic and catabolic enzymes of calcitriol.

Niacinamide, known as nicotinamide, is an important compound functioning as a component of the coenzyme NAD. Its primary significance is in the prevention and/or cure of blacktongue and pellagra. Pellagra is a nutritional disease that occurs due to insufficient dietary amounts of vitamin B3 or the chemical it is made from (tryptophan). Symptoms of pellagra include skin disease, diarrhea, dementia, and depression. In addition, was experiments, revealed, that niacinamide hydroiodide might have role in ophthalmology and parenteral use of niacinamide hydroiodide can treat arteriosclerotic syndromes.

Panthenol (pantothenol) is an alcohol form of the B5 vitamin pantothenic acid. It easily penetrates the skin retaining water and is a humectant, emollient and moisturizer. Panthenol mitigates signs of inflammation and stimulates epithelization. Panthenol comes in two enantiomers, D and L. Only D-panthenol (dexpanthenol) is biologically active, however both forms have moisturizing properties. Because of the ability to attract and hold moisture panthenol is used in skincare products as a humectant. It also has a role as provitamin (called pro-vitamin B5) and is used as a vitamin supplement in complex ( M.V.I. ADULT injection, Hospira Worldwide, Inc.) and alone, and as a cholinergic drug. Panthenol is a highly viscous transparent liquid at room temperature, but salts of pantothenic acid (sodium pantothenate) are powders (typically white). It is soluble in water, alcohol, propylene glycol, ether and chloroform, and slightly soluble in glycerin. Panthenol mixes readily with many different types of ingredients, making it a versatile ingredient to be used in formulas because it improves skin’s barrier function and maintains the proliferation of fibroblasts. In organisms it is quickly oxidized to pantothenate (pantothenic acid). Defficiency of Vitamin B5 results in many dermatological disorder. Due to the fact that only D-Panthenol is converted to Vitamin B5 and not L-Panthenol, the racemic mixture of D- and L- panthenol (DL-panthenol) has only half of the physiological activity of the D-Panthenol. These include stimulation of epithelisation, wound healing effect and anti-infl ammatory effect. Panthenol is FDA approved for cosmetic use and comes either in D form, or as a racemic mixture. It is also in the FDA list of over-the-counter drug products that are not generally recognized as safe and effective or are misbranded: as "Insect Bite and Sting Drug Products" and "Poison Ivy, Poison Oak, and Poison Sumac Drug Products".

Flavin mononucleotide, or riboflavin-5′-phosphate, is a biomolecule produced from riboflavin by the enzyme riboflavin kinase and functions as prosthetic group of various oxidoreductases including NADH dehydrogenase as well as cofactor in biological blue-light photo receptors. Riboflavin (Vitamin B 2) (as riboflavin 5-phosphate sodium) is an ingredient of the FDA approved composition Infuvite Adult, indicated as a daily multivitamin maintenance supplement for adults and children aged 11 and older receiving parenteral nutrition. Infuvite Adult is also indicated in other situations where administration by the intravenous route is required. Such situations include surgery, extensive burns, fractures and other trauma, severe infectious diseases, and comatose states, which may provoke a “stress” situation with profound alterations in the body’s metabolic demands and consequent tissue depletion of nutrients. Flavin mononucleotide is also a component of Cytoflavin, used for the treatment of consequences of cerebral infarction, for the treatment of atherosclerosis, encephalopathy, neurasthenia. Cytoflavin is marketed in Russian Federation.

Acetic acid (a component of vinagre) is used in medicine for the treatment of otitis externa caused by bacterial infections. The solution containing acetic acid was approved by FDA.

Inecalcitol is a calcitriol analog with potential antineoplastic activity patented by a global pharmaceutical company Laboratoire Theramex. Inecalcitol is a potent agonist of vitamin D receptor (VDR). Inecalcitol was shown to be more potent than calcitriol in decreasing tumor cell growth and inducing apoptosis in a number of different model systems including models of breast cancer, prostate cancer, and squamous cell cancer. Importantly, at the doses shown to induce tumor regression in the animal models investigated, Inecalcitol had no major effect on blood calcium levels. In this phase I study, Inecalcitol was found to be well tolerated. Currently, Inecalcitol in combination with the cytotoxic drug, decitabine is undergoing a phase II clinical trial in patients with acute myeloid leukemia who are unfit to receive standard chemotherapy.

Ecalcidene (1-[(1alpha,3beta,5Z,7E,20S)-1,3-dihydroxy-24-oxo-9,10-secochola-5,7,10(19)-trien-24-yl]-piperidine) is a 1-hydroxyvitamin D analogue. Ecalcidene was being developed by Barrier Therapeutics as an oral therapy for psoriasis and acne. However, development has been discontinued.