Indications
Cholecalciferol (vitamin D3) is used to prevent and treat vitamin D deficiency. This is common in people who get little sunlight, older people, people with darker skin, during pregnancy and breastfeeding, and in some gut, liver or kidney conditions. It is used to treat rickets in children and soft bones (osteomalacia) in adults, and is given with Calcium to support bone strength in osteoporosis.
How It Works
Vitamin D3 is changed by the liver and kidneys into its active form. This helps the gut absorb calcium and phosphate, which the body needs for strong bones, healthy muscles and normal nerve function.
Dosage and Administration
- Prevention, adults: commonly 400 to 1000 IU a day.
- Treatment of deficiency: higher doses, such as weekly 20,000 or 40,000 IU capsules for a set number of weeks, followed by a lower maintenance dose, as prescribed. Doses depend on blood vitamin D level.
- Babies and children (drops or syrup): as prescribed. A common preventive dose for infants is 400 IU a day.
- Injection (oral and IM ampoules): high-dose; given by a doctor or nurse, or taken by mouth only when the doctor says so.
- Take with a meal that contains some fat to help absorption.
Interactions
- Thiazide water tablets (such as Hydrochlorothiazide) can raise blood calcium when used with vitamin D.
- High calcium increases the risk of heart rhythm problems with Digoxin.
- Orlistat, Cholestyramine and liquid paraffin reduce vitamin D absorption.
- Phenytoin, Phenobarbital, Carbamazepine, Rifampicin and long-term steroids can lower vitamin D levels, so more may be needed.
Contraindications
- High blood calcium or high calcium in the urine.
- Vitamin D excess (too much vitamin D in the body).
- Calcium kidney stones.
- Allergy to any ingredient.
Side Effects
Side effects are rare at normal doses. Taking too much for a long time raises blood calcium, causing loss of appetite, nausea, constipation, thirst and passing a lot of urine.
Get urgent medical help for: repeated vomiting, severe thirst, confusion, marked weakness, an irregular heartbeat, or signs of an allergic reaction such as swelling of the face or difficulty breathing.
Pregnancy and Lactation
Normal daily doses (commonly 400 IU) are safe and often advised in pregnancy and breastfeeding. Higher treatment doses should be taken only on a doctor’s advice, because too much vitamin D can harm the baby.
Precautions and Warnings
- Do not take more than one vitamin D product at a time unless advised; check combination calcium tablets too.
- Use with care in kidney disease, kidney stones and sarcoidosis.
- With long-term high doses, the doctor may check blood calcium and vitamin D levels.
- For babies, use only the dropper or measure that comes with the product.
Overdose
Overdose causes high blood calcium: nausea, vomiting, thirst, constipation, weakness, confusion and possible kidney damage. Stop taking it and seek medical help straight away.
Therapeutic Class
Vitamin D (fat-soluble vitamin).
Storage
Store below 30°C in a dry place, away from light and out of the reach of children. Do not freeze liquids and ampoules.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.