Available as capsules containing Alfacalcidol 0.25 microgram and 1 microgram supplied under the trade names AlfaDÒ and One-AlphaÒ . A solution containing 0.2 microgram per ml is also available as One-AlphaÒ liquid.

When Vitamin D is ingested in the form usually present in the diet (or produced in the skin by the action of sunlight) it requires to be "activated" by a series of chemical steps before it has any effect in the body. An important action of Vitamin D is to increase the absorption of calcium in the food we eat and so to maintain calcium stores in the body. One step in the activation of the Vitamin takes place in the kidney and requires the presence of a hormone called parathyroid hormone (PTH). When PTH is lacking in the body (which is the case following parathyroidectomy) the kidney step cannot take place and calcium deficiency (hypocalcaemia) results. To get around this problem it is necessary to by-pass the kidney step by taking the "activated" form of Vitamin D which is Alfacalcidol. Alfacalcidol is therefore used to prevent Vitamin D deficiency and thus hypocalcaemia in people who have undergone the surgical removal of their parathyroid glands (parathyroidectomy).

Alfacalcidol can be taken as a capsule or as a liquid for which purpose a measure/dispenser is provided. The individual dose is that required to maintain a normal level of calcium in the blood. It may be adjusted from time to time in response to blood test results. Most adults require to take between 1 microgram and 3 microgram Alfacalcidol daily in order to achieve initial control of their calcium level but the maintenance dose thereafter is normally in the range 0.25 microgram to 1 microgram per day. The dose is taken once a day and at any time of the day.

This medicine is based on the natural active form of a Vitamin and it causes no unexpected side effects. It is important however to ensure that treatment does not result in calcium levels in blood which are too high (hypercalcaemia). If this shows up on a routine blood test, treatment is stopped. The calcium levels usually return to normal about a week later when Alfacalcidol can be safely restarted.

Note that AlfaDÒ and One-AlphaÒ capsules contain arachis (peanut) oil and sesame oil respectively. They should be avoided by people suffering from rare "peanut allergy".

Other medicines or substances which might interfere with your treatment

Some medicines used in the treatment of epilepsy (Phenobarbitone, Phenytoin, EpanutinÒ , Carbamazepine, TegretolÒ ) reduce the levels of vitamin D in the body. Larger doses than usual of Alfacalcidol may be required to compensate for this effect.

Alfacalcidol capsules and liquid should be kept at room temperature but avoiding excessive heat (near a fire, radiator, etc). The liquid medicine must be protected from direct sunlight.

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Ó NHS Tayside; 2006; version 1.0

Disclaimer; no liability whatsoever is accepted for information given and all such information, especially with regard to drug usage (UK version provided), must be checked with a person’s health provider.