Calcichew D3 forte (Calcium carbonate, colecalciferol)

How does it work?

Calcichew D3 Forte chewable tablets contain two active ingredients, calcium carbonate, which is a calcium salt used mainly to supplement calcium in the diet, and colecalciferol, otherwise known as vitamin D3.

Calcium is an essential mineral needed for many purposes in the body, including the formation of strong bones. Calcium requirements are raised in the years following the menopause, and when dietary intake of calcium is low. Calcium supplements have been shown to help prevent bone loss.

Calcium is found in milk and dairy products, as well as spinach, nuts and sardines. Usually, calcium requirements are met from the diet. However, there are times when the amount of calcium required is increased, such as during growth, pregnancy, when breastfeeding or with advancing age. When there is insufficient calcium in the diet to meet the body's needs, supplements are needed, otherwise calcium deficiency can occur.

Calcium supplements are useful in osteoporosis; a calcium intake that is twice the recommended daily allowance (RDA) slows the rate of bone loss and reduces the risk of fractures.

Colecalciferol, also known as vitamin D3, is normally obtained primarily from sunlight acting on the skin. It is also consumed in the diet in oily fish and milk products. Vitamin D deficiency develops when there is inadequate exposure to sunlight, such as in elderly people with reduced mobility or who are housebound, or when there is a lack of the vitamin in the diet.

Vitamin D is needed for calcium to be absorbed from the gut, and deficiency can lead to low calcium levels and subsequent weakening of bones. This is known as osteomalacia. Vitamin D supplements correct vitamin D deficiency and improve calcium absorption from the gut.

Calcium and vitamin D supplements are used to treat osteomalacia and osteoporosis. By increasing vitamin D and calcium in the body they help strengthen the bones. They are also used to supplement the diet during pregnancy, when there are increased requirements for these nutrients. Calcium and vitamin D supplements are also given to prevent and treat dietary deficiency, for example in the housebound elderly.

What is it used for?

  • Osteoporosis.
  • Softening of the bones when there is lack of vitamin D in the body (osteomalacia).
  • Prevention and treatment of vitamin D and calcium deficiency, for example in pregnancy and in housebound elderly people.

How do I take it?

  • Calcichew D3 Forte chewable tablets should be chewed or sucked and not swallowed whole. They can be taken either with or without food.
  • Adults and elderly people should take two tablets daily, preferably one in the morning and one in the evening.


  • If you have mild to moderate kidney failure or raised levels of calcium in your urine (hypercalciuria) the amount of calcium in your blood and urine should be regularly monitored while you are taking this medicine.
  • If you have a history of kidney stones, the amount of calcium excreted in your urine should be monitored while you are taking this medicine.
  • It is recommended that people receiving long-term treatment with this medicine are monitored for the amount of calcium in their blood and urine, and their kidney function.

Use with caution in

  • People with a history of kidney stones (nephrolithiasis).
  • Kidney failure.
  • Sarcoidosis.
  • People with osteoporosis due to long periods of inactivity, for example prolonged bed-rest or paralysis of the legs.

Not to be used in

  • Children under 12 years of age.
  • People with a high level of calcium in their blood (hypercalcaemia), for example as a result of bone marrow cancer, cancer that has spread to the bones, sarcoidosis or overactivity of the parathyroid glands (hyperparathyroidism).
  • People with very high levels of calcium in their urine (hypercalciuria).
  • Kidney stones.
  • People with vitamin D poisoning.
  • Severe kidney failure.
  • Calcichew D3 Forte chewable tablets contain soya oil and should not be taken by people who are allergic to peanuts or soya.
  • Calcichew D3 Forte chewable tablets contain sorbitol, isomalt and sucrose and should not be taken by people with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption or sucrase-isomaltase insufficiency.
  • Calcichew D3 Forte chewable tablets contain aspartame, which is a source of phenylalanine. As a result, they may not be suitable for people with an inherited disorder of protein metabolism called phenylketonuria.

This medicine should not be used if you are allergic to any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.

If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

  • This medicine is safe to take during pregnancy at the recommended doses. However, you should check with your doctor or midwife if it is necessary for you to take a calcium and vitamin D supplement during your pregnancy. Not all pregnant women need to take supplements; you may be getting enough nutrients from your diet.
  • Calcium and vitamin D pass into breast milk and for this reason, if you are breastfeeding you should only take this medicine on the advice of your doctor.

Label warnings

  • This medication is to be sucked or chewed.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.

  • Constipation.
  • Diarrhoea.
  • Pain in the stomach and abdominal area.
  • Excess gas in the stomach and intestines (flatulence).
  • Nausea.
  • Skin rashes.
  • High blood calcium level (hypercalcaemia).
  • High calcium levels in the urine.

The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.

For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to make sure that the combination is safe.

You should not take any other calcium or vitamin D supplements (including those found in multivitamins) in combination with this medicine, unless specifically prescribed by your doctor.

Calcium carbonate may reduce the absorption of tetracycline antibiotics (eg tetracycline, minocycline, doxycycline) and quinolone antibiotics (eg ciprofloxacin, norfloxacin, nalidixic acid) from the gut and could make them less effective. If you are prescribed a course of one of these types of antibiotics it is recommended that you take the antibiotic at least two hours before or four to six hours after taking this medicine. Ask your pharmacist for further advice.

Calcium salts may also reduce the absorption from the gut of the following medicines:

  • bisphosphonates, eg etidronate
  • eltrombopag
  • iron supplements such as ferrous sulphate
  • levothyroxine
  • sodium fluoride
  • strontium ranelate
  • zinc.

To avoid the calcium stopping these medicines from being adequately absorbed, your dose of Calcichew D3 Forte tablets should be separated from these medicines by at least four hours.

Thiazide diuretics, such as bendroflumethiazide, reduce the amount of calcium excreted in the urine, and this can increase the amount of calcium in the blood. If you are taking a thiazide diuretic in combination with this medicine you should have regular blood tests to monitor the level of calcium in your blood.

People taking digoxin or other cardiac glycosides may have an increased risk of abnormal heart rhythms if they experience abnormally high blood calcium levels while taking this medicine.

The following medicines may decrease the absorption of vitamin D from the gut and should not be taken at the same time of day as this medicine:

  • orlistat
  • colestyramine
  • colestipol.

If you are taking any of the following medicines you may need a larger than normal dose of vitamin D. Ask your doctor for advice:

  • carbamazepine
  • phenobarbital
  • phenytoin.

Other medicines containing the same active ingredients

Accrete D3Adcal D3Cacit D3
Calceos Calcichew D3 Kalcipos-D
Natecal D3

Calfovit D3 and Sandocal+D contain other salts of calcium in combination with vitamin D3.