Along with its needed effects, a dietary supplement may cause some unwanted effects. Alfacalcidol, calcifediol, calcitriol, dihydrotachysterol, and ergocalciferol do not usually cause any side effects when taken as directed. However, taking large amounts over a period of time may cause some unwanted effects that can be serious.
Check with your doctor immediately if any of the following side effects occur:
Late symptoms of severe overdose
Check with your doctor as soon as possible if any of the following side effects occur:
Early symptoms of overdose
Late symptoms of overdose
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
For individuals taking vitamin D without a prescription:
If you are taking this medicine for a reason other than as a dietary supplement, your doctor should check your progress at regular visits to make sure that it does not cause unwanted effects.
Do not take any nonprescription (over-the-counter [OTC]) medicine or dietary supplement that contains calcium, phosphorus, or vitamin D while you are taking any of these dietary supplements unless you have been told to do so by your health care professional. The extra calcium, phosphorus, or vitamin D may increase the chance of side effects.
Do not take antacids or other medicines containing magnesium while you are taking any of these medicines. Taking these medicines together may cause unwanted effects.
For use as a dietary supplement:
If you have any questions about this, check with your health care professional.
For individuals taking the oral liquid form of this dietary supplement:
While you are taking alfacalcidol, calcifediol, calcitriol, dihydrotachysterol, doxercalciferol or paricalcitol , your health care professional may want you to follow a special diet or take a calcium supplement. Be sure to follow instructions carefully. If you are already taking a calcium supplement or any medicine containing calcium, make sure your health care professional knows.
The dose medicines in this class will be different for different patients. Follow your doctor’s orders or the directions on the label. The following information includes only the average doses of these medicines. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
Call your doctor or pharmacist for instructions.
For use as a dietary supplement: If you miss taking a dietary supplement for one or more days there is no cause for concern, since it takes some time for your body to become seriously low in vitamins. However, if your health care professional has recommended that you take this dietary supplement, try to remember to take it as directed every day.
If you are taking this medicine for a reason other than as a dietary supplement and you miss a dose and your dosing schedule is:
If you have any questions about this, check with your health care professional.
Keep out of the reach of children.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Do not keep outdated medicine or medicine no longer needed.
If you are taking a dietary supplement without a prescription, carefully read and follow any precautions on the label. For these supplements, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to medicines in this group or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Problems in children have not been reported with intake of normal daily recommended amounts. Some studies have shown that infants who are totally breast-fed, especially with dark-skinned mothers, and have little exposure to sunlight may be at risk of vitamin D deficiency. Your health care professional may prescribe a vitamin/mineral supplement that contains vitamin D. Some infants may be sensitive to even small amounts of alfacalcidol, calcifediol, calcitriol, dihydrotachysterol, or ergocalciferol. Also, children may show slowed growth when receiving large doses of alfacalcidol, calcifediol, calcitriol, dihydrotachysterol, or ergocalciferol for a long time.
Studies on doxercalciferol or paricalcitol have been done only in adult patients, and there is no specific information comparing the use of doxercalciferol or paricalcitol in children with use in other age groups.
Problems in older adults have not been reported with intake of normal daily recommended amounts. Studies have shown that older adults may have lower blood levels of vitamin D than younger adults, especially those who have little exposure to sunlight. Your health care professional may recommend that you take a vitamin supplement that contains vitamin D.
It is especially important that you are receiving enough vitamin D when you become pregnant and that you continue to receive the right amounts of vitamins throughout your pregnancy. The healthy growth and development of the fetus depend on a steady supply of nutrients from the mother.
You may need vitamin D supplements if you are a strict vegetarian (vegan-vegetarian) and/or have little exposure to sunlight and do not drink vitamin D-fortified milk.
Taking too much alfacalcidol, calcifediol, calcitriol, dihydrotachysterol, or ergocalciferol can also be harmful to the fetus. Taking more than your health care professional has recommended can cause your baby to be more sensitive than usual to its effects, can cause problems with a gland called the parathyroid, and can cause a defect in the baby’s heart.
Doxercalciferol or paricalcitol have not been studied in pregnant women. However, studies in animals have shown that paricalcitol causes problems in newborns. Before taking this medicine, make sure your doctor knows if you are pregnant or if you may become pregnant.
It is especially important that you receive the right amounts of vitamins so that your baby will also get the vitamins needed to grow properly. Infants who are totally breast-fed and have little exposure to the sun may require vitamin D supplementation. However, taking large amounts of a dietary supplement while breast-feeding may be harmful to the mother and/or baby and should be avoided.
Only small amounts of alfacalcidol, calcifediol, calcitriol, or dihydrotachysterol pass into breast milk and these amounts have not been reported to cause problems in nursing babies.
It is not known whether doxercalciferol or paricalcitol passes into breast milk. Be sure you have discussed the risks and benefits of the supplement with your doctor.
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other Medical Problems
The presence of other medical problems may affect the use of dietary supplements in this class. Make sure you tell your doctor if you have any other medical problems, especially: