Cholecalciferol (Vit. D3)

Cholecalciferol (Vitamin D3) is a fat-soluble sterol that plays a vital role in regulating calcium and phosphate balance in the body . It is needed for healthy bones, muscles, and nerves by helping the body absorb calcium from food and supplements . Vitamin D3 is synthesized in the skin from 7-dehydrocholesterol upon sun exposure or obtained from diet and supplements . The active form calcitriol (1,25-dihydroxyvitamin D) binds to vitamin D receptors, enhancing intestinal calcium and phosphate absorption and regulating bone resorption .

Osteoporosis: Prevention and treatment of bone loss in the elderly Rickets: Prevention and treatment of bone softening in children Osteomalacia: Bone softening in adults Hypoparathyroidism: Low calcium levels due to parathyroid hormone deficiency Vitamin D Deficiency: Low serum 25-hydroxyvitamin D levels Pre-eclampsia prevention during pregnancy – Vitamin D is essential for the growing infant Immune system support – Vitamin D plays a vital role in boosting immunity

Vitamin D Analog / Vitamin in Bone Formation / Vitamin-D Preparations

Vitamin D3 (cholecalciferol) is a prohormone that regulates calcium and phosphate balance in the body . It is first hydroxylated in the liver to 25-hydroxyvitamin D (calcifediol) and then in the kidney to 1,25-dihydroxyvitamin D (calcitriol), the active form . Calcitriol increases intestinal absorption of calcium and phosphate, regulates bone resorption, and increases renal calcium reabsorption . It works by binding to vitamin D receptors (VDRs) present in virtually every cell and regulates the synthesis of hundreds of enzymes . As a fat-soluble vitamin, it has a half-life of about 50 days.

The active form of vitamin D3, calcitriol (1,25-dihydroxyvitamin D), binds to vitamin D receptors in the mucosal cytoplasm of the intestine . This binding increases calcium absorption through the formation of calcium-binding proteins . It also increases serum calcium concentrations by increasing osteoclastic resorption and increasing distal renal tubular reabsorption of calcium . As a result, bone mineralization is improved, and rickets, osteomalacia, and osteoporosis can be prevented .

Adult Dose: Oral /IM: Nutritional deficiency Colecalciferol (Vitamin D3) is recommended 5-10 mcg or 1-2ml (200-400 IU)/day Osteoporosis Prophylaxis and treatment >50 years: 800-1000 IU (20-25 mcg) PO once daily with calcium supplements. May also be given via IM inj. Hypoparathyroidism 50,000-200,000 IU (0.625-5 mg) PO once daily with calcium supplements. May also be given via IM inj. Child Dose: Nutritional Supplementation RDA 0-12 months: 400 IU (10 mcg) PO once daily 1-18 years: 600 IU (15 mcg) PO once daily Vitamin D-Resistant Rickets 12,000-500,000 IU (0.3-12.5 mg) PO once daily Familial Hypophosphatemia 40,000-80,000 IU (1-2 mg) PO once daily with phosphate supplements; may be reduced after stage of growth is complete

Capsule – Adults Treatment of Vitamin D3 deficiency: 40,000 IU once weekly for 7 weeks. Maintenance therapy: 1,400–2,000 IU/day. Prevention of Vitamin D3 deficiency: 20,000 IU every 4 weeks. Treatment of osteoporosis: 20,000 IU once monthly. Capsule – Children (12–18 years) Treatment of deficiency: 20,000 IU every 2 weeks for 6 weeks. Prevention of deficiency: 20,000 IU every 6 weeks. Film-Coated Tablet / Oroflash / Chewable Tablet 1,000–2,000 IU daily (1–2 tablets), or as directed by the physician. Take with food or within 1 hour of a meal. Chewable tablets should be chewed and swallowed. Oral Solution Up to 1 year: 400 IU daily. 1–18 years: 600 IU daily. Injection (IM) – Treatment Rickets: 1 ampoule every 2 weeks for 1 month, then 1 ampoule every 4 months. Osteoporosis: 1 ampoule every 2 weeks for 3 months. Osteomalacia: 1 ampoule every 2 weeks for 3 months. Hypocalcemia-induced tetany: 1 ampoule every 4 months (up to 2 ampoules if required). Menopause: 1 ampoule every 6 months. Vitamin D3 deficiency: Repeat after 1–6 months. Injection (IM) – Prevention Pregnancy: 1/2 ampoule during the 6th–7th month. Lactation: 1/2 ampoule every 6 months. Children up to 5 years: 1 ampoule every 6 months. Adolescents: 1 ampoule every 6 months. Elderly: 1/2 ampoule every 3 months.

Generally all nutritional supplements are considered to be safe and well tolerable. However, few side-effects can generally occur including hypercalcaemia syndrome or Calcium intoxication (depending on the severity and duration of hypercalcaemia), occasional acute symptoms include anorexia, headache, dry mouth, nausea, vomiting, abdominal pain or stomach ache and constipation with the administration of Colecaciferol.

People with the following conditions should exercise caution when considering taking vitamin D supplements: High blood Calcium or Phosphorus level Heart problems Kidney disease Vitamin D must be taken with adequate amounts of both Calcium and Magnesium supplementation. When Calcium level is low (due to insufficient vitamin D and calcium intake), the body activates the parathyroid gland, which produces PTH (parathyroid hormone). This hormone kick starts vitamin D hormone production and assists removal of Calcium from the bones to be used in more important functions such as neutralizing body acidity. Lactation: Drug is distributed into breast milk; use with caution

Colecalciferol is contraindicated in all diseases associated with hypercalcaemia. It is also contraindicated in patients with known hypersensitivity to Colecalciferol (or medicines of the same class) and any of the constituent excipients. Colecalciferol is contraindicated if there is evidence of vitamin D toxicity.

Increased risk of hypercalcaemia if given with thiazide diuretics, calcium or phosphate. Antiepileptics (e.g. carbamazepine, phenobarbitone, phenytoin & primidone) may increase vitamin D requirements. Rifampicin & isoniazid may reduce efficacy of vitamin D. Corticosteroids may counteract the effect of vitamin D. Digoxin or any cardiac glycoside. Reduced absorption when taken with cholestyramine, colestipol, mineral oil, orlistat. Ketoconazole.

The most serious consequence of acute or chronic overdose is hypercalcemia (Vitamin D toxicity). Symptoms include nausea, vomiting, polyuria, anorexia, weakness, lethargy, thirst, and constipation. Chronic overdose may cause calcification of blood vessels and organs. Treatment includes discontinuation of Vitamin D and rehydration.

Store in a cool, dry place at a temperature below 25°C, protected from light. Keep out of reach of children. Store the injection at 2°C–8°C.