Vitamin D3 is a form of vitamin D that helps the body absorb calcium and other minerals, which are important for things like healthy bones and immune function.
It’s also a popular nutritional supplement and a staple in drugstore vitamin aisles, but between ABC and 123 it can sometimes feel overwhelming. What exactly is vitamin D3 and how is it different from vitamin D? Who should take supplements?
We spoke to experts to learn more about vitamin D3. Here’s what you need to know about vitamin D3 benefits, sources, deficiencies, side effects, and more.
What is vitamin D3?
Vitamin D (calciferol) is a fat-soluble vitamin that plays an important role in many bodily functions, including maintaining bone health and supporting immune function, says a clinical nutritionist at the Center for Cardiovascular Disease Prevention at New York University Langone Health. Heather Hodson said. He told TODAY.com.
There are two main forms: vitamin D3 and vitamin D2.
Vitamin D3, also known as cholecalciferol, is a form of vitamin D that is synthesized in the skin when exposed to sunlight, Hodson said. “It can also be obtained from dietary sources such as fish and supplements,” Hodson added.
Once vitamin D3 is synthesized in the skin or ingested, it is converted to calcidiol in the liver and ultimately to calcitriol, the active form of vitamin D, Hodson says.
According to the National Institutes of Health, vitamin D2, also known as ergocalciferol or “previtamin D,” is usually made artificially and added to foods.
Vitamin D3 benefits
- Supports bone health
- strengthens the immune system
- Promotes heart and brain health
- reduces inflammation
According to Hodson, vitamin D3 plays an important role in supporting and maintaining healthy bones. It does this by regulating calcium and phosphorous levels in the blood and promoting the absorption of these minerals by the intestines.
It’s also essential for bone growth and remodeling, according to the NIH. Vitamin D3 helps prevent bone diseases such as osteoporosis and bone loss.
“It really supports our bone health, so it keeps our skeletal system nice and strong,” Zell Morefield, a transplant dietitian at the Mayo Clinic, told TODAY.com. Vitamin D3 also supports healthy muscle and nerve function.
According to the Mayo Clinic, vitamin D3 strengthens the immune system to help the body fight bacteria and viruses, and also has neuroprotective properties that support brain cell activity.
“It also has several different anti-inflammatory and antioxidant properties, which are good for overall cellular function and help with many small cellular processes,” Morefield says.
How much vitamin D3 do I need?
According to the NIH, the Recommended Dietary Allowance (RDA) for vitamin D is the daily intake sufficient to maintain bone health and normal calcium levels in a healthy person. This depends on your age.
- Infants 0-12 months: 10 mcg (400 IU)
- Children 1-18 years: 15 mcg (600 IU)
- Adults 18-70 years: 15 mcg (600 IU)
- Adults 70 years and older: 20 mcg (800 IU)
What are the sources of vitamin D3?
You can get vitamin D3 in three main ways: through diet, sunlight, and supplements.
Food sources of vitamin D3
Although few foods are naturally rich in vitamin D3, experts note that certain foods, especially in the United States, are fortified with vitamin D3. Dietary sources of vitamin D3 include:
- Fatty fish (salmon, tuna, sardines, trout)
- egg yolk
- organ meat
- fish liver oil
- fortified milk
- fortified orange juice
- fortified cereal
The other form, vitamin D2, can be obtained from plant-based sources such as fortified plant milks, juices, and mushrooms exposed to ultraviolet light, Hodson says.
ultraviolet light
“The only other way to get vitamin D is through sunlight,” Morefield says. When ultraviolet (UV) radiation from sunlight hits uncovered skin, vitamin D is produced in the body, which triggers the synthesis of previtamin D3, which is converted to the vitamin. D3, by NIH.
“Typically, five to 15 minutes of sun exposure, for example when you’re walking down the street, allows your skin to synthesize vitamin D from sunlight,” says Morefield.
The amount of vitamin D your body produces depends on several factors. According to the Mayo Clinic, these include location, season, time of day, cloud cover, air pollution, sunscreen, protective clothing, age, and skin pigmentation or melanin content.
supplement
Dietary supplements can be used if you don’t get enough vitamin D from your diet or sunlight, or if you have a vitamin D deficiency due to a medical condition or medication.
According to the NIH, vitamin D supplements may contain either vitamin D3, which often comes from animal sources but can also be sourced from lichens, or vitamin D2, which comes from plant sources. Most standard multivitamins also contain vitamin D, Morefield says.
“Research has shown that compared to vitamin D2, vitamin D3 is more easily absorbed and may be more effective at maintaining desirable vitamin D levels,” says Hodson.
Who should take vitamin D3?
Most people get enough vitamin D from sunlight, food, and multivitamins, but some people may benefit from adding vitamin D3.
If you are deficient in vitamin D3, we recommend taking vitamin D3 supplements. Hodson says health care providers can determine this with a test that measures vitamin D levels in the blood.
Vitamin D deficiency usually occurs when people don’t get enough vitamin D from their diet or sunlight. Inability to properly synthesize or absorb vitamin D. Or, experts say, you have certain medical conditions or are taking medications that affect your vitamin D levels.
According to Dr. Hodson, people with limited exposure to sunlight, such as those who spend very limited time outdoors or live in cooler regions, may be at higher risk of vitamin D deficiency. .
“During the colder months, we are often dressed head-to-toe in winter clothes, so very little skin is exposed to sunlight for vitamin D3 synthesis,” Hodson added.
According to the Cleveland Clinic, people with darker skin that has more melanin may synthesize less vitamin D. Older people synthesize less vitamin D and often spend more time indoors, putting them at increased risk of vitamin D deficiency, Morefield added.
Experts say some medical conditions can affect the absorption and synthesis of active vitamin D. These include:
- Irritable bowel disease (Crohn’s disease, ulcerative colitis)
- celiac disease
- cystic fibrosis
- liver or kidney disease
Hodson added that people with a history of gastrointestinal surgery, such as weight-loss surgery for obese patients or small bowel resection surgery, may have difficulty absorbing vitamin D3.
“People with these conditions may benefit from additional vitamin D, but they should discuss with their health care provider what form is most appropriate,” Hodson said. To tell.
Certain medications can also lower vitamin D levels. According to the Cleveland Clinic, these include, but are not limited to:
- laxative
- Steroids (prednisone)
- cholesterol lowering drugs
- seizure medication
Symptoms of vitamin D deficiency
“Vitamin D deficiency is not always characterized by significant symptoms,” Hodson says. Some people may have no signs or symptoms of vitamin D deficiency, Hodson added.
Potential symptoms of vitamin D deficiency include:
- muscle pain
- Weakness
- bone pain
- mood changes
Over time, vitamin D deficiency can lead to complications such as osteoporosis, osteomalacia (softening of the bones), and bone fractures, according to the Cleveland Clinic.
“In older adults, deficiencies can increase the risk of falls,” Hodson says.
In severe cases in children, vitamin D deficiency can cause bow legs and rickets, which can lead to skeletal deformities, Hodson added.
Experts stress that the only way to know if you have a vitamin D deficiency is to get tested. Hodson added that semi-regular monitoring of vitamin D levels (e.g., at annual checkups) may help treat or prevent vitamin D deficiency in a timely manner.
Vitamin D3 dosage
“It’s always a good idea to talk to your health care professional and have your vitamin D levels checked before you start taking supplements,” says Hodson.
For healthy children and adults, the recommended daily intake of vitamin D is 400 to 600 IU. “This is the standard amount that most of the population needs to support basic functioning, but if there are deficiencies, the numbers can vary widely,” Morefield says.
Most vitamin D3 supplements available over the counter are sold in doses between 1000 and 5000 IU, although some are higher. “If there is a dosage that is right for you, recommend that dosage to your health care provider and do not exceed that dosage,” Hodson added.
TODAY.com previously reported that research shows that healthy adults without vitamin D3 deficiency likely would not benefit from taking extra vitamin D3 through supplements.
Side effects and risks of vitamin D3
Vitamin D3 is generally safe when taken properly and as directed. However, Hodson says it’s important not to exceed the prescribed or recommended dose, as taking too much vitamin D3 can cause vitamin D toxicity.
“Vitamin D is a fat-soluble vitamin, so if you take too much of it, it’s not excreted in the urine and accumulates in your body,” says Hodson. Taking too many vitamin D3 supplements can cause vitamin D3 to accumulate in the body and reach toxic levels.
According to Hodson, vitamin D toxicity can cause symptoms such as:
- constipation
- nausea
- vomiting
- decreased appetite
- hypercalcemia
If you experience any side effects, consult your doctor. “When choosing a supplement, choose a trusted brand that has been third-party tested,” says Hodson.
