Cholecalciferol (vitamin D₃) is used as a dietary supplement when the amount of vitamin D in the diet is not enough. People most at risk for vitamin D deficiency are older adults, breastfed infants, people with dark skin, obese people, and those with limited sun exposure, or gastrointestinal disease (GI; affecting the stomach or intestines) such as Crohn's disease or celiac disease. Cholecalciferol (vitamin D₃) is also used along with calcium to prevent and treat bone diseases such as rickets (softening and weakening of bones in children caused by lack of vitamin D), osteomalacia (softening and weakening of bones in adults caused by lack of vitamin D), and osteoporosis (a condition in which the bones become thin and weak and break easily). Cholecalciferol (vitamin D₃) is in a class of medications called vitamin D analogs. Cholecalciferol is needed by the body for healthy bones, muscles, nerves, and to support the immune system. It works by helping the body to use more of the calcium found in foods or supplements.

Cholecalciferol (vitamin D₃) comes as a capsule, gel capsule, chewable gel (gummy), tablet, and liquid drops to take by mouth. It is usually taken once or twice daily depending on the preparation, your age, and your medical condition(s). Cholecalciferol is available without a prescription, but your doctor may prescribe cholecalciferol to treat certain conditions. Check with your doctor or pharmacist before taking a cholecalciferol (vitamin D) supplement. Take cholecalciferol at around the same time every day. Follow the directions on your product label or doctor's instructions carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take cholecalciferol exactly as directed. Do not take more or less of it or take it more often than recommended by your doctor.

Cholecalciferol liquid drops may be added to your child's food or drink.

Cholecalciferol supplements are available alone and in combination with vitamins, and in combination with medications.

Before taking cholecalciferol,

• tell your doctor and pharmacist if you are allergic to cholecalciferol, any other medications, or any of the ingredients in cholecalciferol products. Ask your pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: calcium supplements, carbamazepine (Equetro, Teril, others), cholestyramine (Prevalite), multivitamins, orlistat (Alli, Xenical), phenobarbital, phenytoin (Dilantin), prednisone (Rayos), thiazide diuretics (''water pills''), or other cholecalciferol (vitamin D) supplements and fortified foods. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have or have ever had hyperparathyroidism (a condition in which the body produces too much parathyroid hormone [PTH; a natural substance needed to control the amount of calcium in the blood]), kidney disease, or have high blood levels of calcium.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking cholecalciferol (vitamin D₃), call your doctor.

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

Symptoms of overdose may include:

• loss of appetite
• weight loss
• nausea
• vomiting
• constipation
• weakness

Keep this vitamin in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

When cholecalciferol (vitamin D₃) is used to treat and prevent bone diseases, you should eat and drink of foods and drinks that are rich in calcium. If you find it difficult to eat enough calcium-rich foods, tell your doctor. In that case, your doctor can prescribe or recommend a calcium supplement.

Unless your doctor tells you otherwise, continue your normal diet.

Cholecalciferol (vitamin D₃) may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• loss of appetite
• weight loss
• nausea
• vomiting
• constipation

Cholecalciferol (vitamin D₃) may cause other side effects. Call your doctor if you have any unusual problems while taking this vitamin.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Keep all appointments with your doctor.

Ask your pharmacist any questions you have about cholecalciferol.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

• Fosamax® Plus D (containing alendronate, cholecalciferol)
• Tri-Vi-Sol® (containing Vitamin A, Vitamin C, Vitamin D)
• Viactiv® Calcium Plus Vitamin D (containing calcium, vitamin D)