Vitamin D3 (cholecalciferol) is a form of vitamin D naturally found in some foods and available as a supplement. Your body also creates vitamin D when your skin is exposed to natural sunlight. Vitamin D3 is needed for many body functions, including bone, heart, and mental health.
Maintaining your vitamin D levels through diet or supplementation can benefit your health in several ways.
Improves Bone Health
One of the main roles of vitamin D3 in the body is supporting bone health. It helps your body absorb calcium, a mineral essential for maintaining bone structure, keeping bones healthy and strong. Without enough vitamin D3, your bones may become brittle and thin, raising your risk of fractures.
Vitamin D3 helps prevent and treat the softening and weakening of bones in children (rickets) and adults (osteomalacia). In older adults, vitamin D3 helps prevent osteoporosis, a condition where the bones are weak and brittle. Taking vitamin D3 daily can help prevent these bone-related conditions.
Vitamin D3 also helps keep muscles strong, supports balance, and lowers the risk of falling. Low vitamin D levels can lead to poor muscle strength and raise the risk of weakness and pain.
Protects Heart Health
Vitamin D3 helps maintain your blood pressure and supports the health of cells that make up your heart and blood vessels. The vitamin also helps with inflammation, the stiffness of blood vessels, and cholesterol levels. Each of these concerns can raise your risk for cardiovascular disease.
Multiple studies have found that high vitamin D levels in the blood are associated with a lower risk of cardiovascular disease, including heart attack, stroke, and death. Research is conflicting, as other studies have not found the same effects of vitamin D on heart health.
Improves Mental Health System
Vitamin D3 is involved in many brain processes, and research suggests it may help treat anxiety and depression symptoms. Several studies have found an increase in depression in people with low vitamin D levels. Other studies have found no relationship between vitamin D levels and mental health.
Some foods naturally contain vitamin D3, like fatty fish (trout, salmon, tuna), fish liver oils, and fortified dairy products. Here is how much vitamin D3 is found in some foods:
- Cod liver oil: 1,360 International Units (IU) (34 micrograms) per 1 tablespoon, 170% of your Daily Value (DV)
- Cooked rainbow trout: 645 IU (16.2 micrograms) per 3 ounces, 81% of the DV
- Cooked sockeye salmon: 570 IU (14.2 micrograms) per 3 ounces, 71% of the DV
- Raw mushrooms exposed to UV light: 366 IU (9.2 micrograms) per 1/2 cup, 46% of the DV
- Two-percent cow’s milk (fortified): 3,120 IU (3 micrograms) per 1 cup, 15% of the DV
- One egg (scrambled): 44 IU (1.1 micrograms), 6% of the DV
Direct sunlight can also provide vitamin D3 through the skin. However, the season, time of day, cloud coverage, smog, and sunscreen can affect how much vitamin D3 your body makes from the sun. Getting vitamin D from sunlight is more difficult if you are older or have darker skin.
Vitamin D3 is available in supplement form as a capsule, gel, gummy, liquid, or tablet. You can take vitamin D3 alone or in combination with other supplements. Most multivitamins contain vitamin D.
The supplement should be taken by mouth once or twice a day, depending on what your healthcare provider recommends. You can take vitamin D3 with or without food and at any time of the day.
Talk with your healthcare provider before taking a vitamin D3 supplement to determine if it would benefit you and how much you should take.
Dosage
Your vitamin D3 dosage depends on why you are taking the supplement and which form. The recommended dietary allowance (RDA) for vitamin D in adults is 600 IU or 15 micrograms. The RDA is the same for people who are pregnant or lactating. The RDA for adults older than 70 years old is 800 IU (20 micrograms).
Vitamin D is safe in doses up to 4,000 IU (100 micrograms) daily in adults. In general, you should not take more than 4,000 IU of vitamin D per day unless your healthcare provider tells you. For example, a provider may recommend taking vitamin D3 doses of 50,000 IU (1,250 micrograms) for six to 12 weeks if you have very low vitamin D levels.
Vitamin D is considered safe when taken in appropriate, recommended dosages. To ensure you are taking an appropriate dose, follow the instructions provided by your healthcare provider and on the supplement label.
Potential Drug Interactions
Vitamin D3 may interact with other medications you are taking. Examples include:
- Lipitor (atorvastatin): Vitamin D3 may lower how well your body absorbs Lipitor, a statin medication used to treat high cholesterol. Be cautious if you are also taking other statin medications like Mevacor (lovastatin) and Zocor (simvastatin). It is not likely that the vitamin D3 supplement will affect cholesterol levels in the body.
- Heart medications: High doses of vitamin D3 can raise calcium levels in your body. High calcium levels can affect how fast your heart beats and how well other heart medications work. Examples include Lanoxin (digoxin), Cardizem (diltiazem), and Calan (verapamil).
- Certain diuretics: Combining high doses of vitamin D3 with thiazide diuretics can raise calcium levels in the body. This happens because diuretics lower the amount of calcium that leaves the body through urine (pee). Examples of thiazide diuretics include Microzide (hydrochlorothiazide) and Diuril (chlorothiazide).
The highest and safest tolerable dose for vitamin D3 in all adults is 4,000 IU (100 micrograms). Taking doses larger than 4,000 IU can raise your risk for side effects.
Very high doses of vitamin D3 supplements can be dangerous, leading to side effects like high calcium levels, nausea, vomiting, and muscle weakness. High vitamin D levels can also cause your kidneys and heart to stop working properly. These side effects are unlikely if your daily dose is less than 10,000 IU (250 micrograms).
Supplementing with vitamin D3 is safe and has a low chance of side effects if taken at a normal dosage. Potential side effects of vitamin D3 include:
- Loss of appetite
- Weight loss
- Nausea
- Vomiting
- Constipation
Vitamin D3 (cholecalciferol) is a form of vitamin D naturally found in some foods and available as a supplement. Vitamin D3 is needed for many body functions, including bone, heart, and mental health. If taken at a normal dosage, the supplement is considered safe and has a low chance of side effects.
If you want to take vitamin D3, talk with your healthcare provider. They can help you decide if the supplement is beneficial and safe.
