What Is Vitamin D3?

In This Article

Vitamin D3 also known as the “sunshine vitamin” is produced in the skin when it is exposed to sunlight. When exposure happens, a hormone is produced from cholesterol and this allows the vitamin to be produced through the skin. It circulates in the bloodstream and aids in the absorption of calcium and phosphorus.

If there is not enough of this vitamin in the body to help absorb the calcium the body will pull it from the bones. Without proper absorption of calcium for vitamin D3, the bones will get weak and this can lead to fractures and osteoporosis.

Close up capsules of vitamin D3
Olga Shumitskaya / Getty Images

What It Is

There are two different forms of vitamin D. Both are found in dietary supplements or fortified foods. Vitamin D2 (ergocalciferol) is known to be man-made and comes from fortified foods and plant sources.

Vitamin D3 (cholecalciferol) is found in animal-based foods and produced in our bodies through the sunlight and ultraviolet light. Vitamin D3 is also known to increase vitamin D levels overall in the blood.

Individuals who use a lot of sunscreen and who do not have much exposure to the sun due to location, weather, and skin pigmentation don’t get the proper amounts of vitamin D. Since there are few foods that have the nutrient naturally, supplements are an option.

Sources

There are three ways that you can get vitamin D3. It comes from animal-based foods, the sun, and supplements.

Some of the foods that naturally have vitamin D3 include:

  • Beef liver
  • Cheese
  • Egg yolks
  • Fresh salmon
  • Mackerel
  • Halibut
  • Sardines
  • Trout
  • Butter
  • Cod liver oil

There are some foods and juices that are also fortified with the vitamin. You can easily incorporate these foods into your diet throughout the day. If you are taking supplements, check with a licensed medical professional for appropriate dosage.

Health Benefits

Vitamin D3 offers many health benefits. It is known to help strengthen bones and muscles, boost immunity, increase mood, aid in weight loss, and improve heart function.

Bones

Vitamin D is known to help both the muscles and bones. It enhances the absorption of calcium in the small intestine. Research shows that vitamin D can aid in reducing fractures and improve muscle strength. In addition, high levels of dietary vitamin D3 may be suitable for achieving a higher peak bone mass in adulthood and thereby preventing osteoporosis.

Immunity

Research has shown that vitamin D may help protect against acute respiratory infections. “The study found that daily or weekly intake of the supplement benefited individuals who had a deficiency (blood levels below 10 mg/dl) and cut their risk of respiratory infection in half.” All the individuals who participated experienced some benefit by taking regular supplements.

Mood

There were studies conducted to see if vitamin D had a direct correlation with improving depression. The findings suggested that this type of study is an important area of future research.

“The outcome did suggest, exercising outdoors, eating vitamin D3 rich foods and taking supplements to improve overall mental well-being, it could be a solution for individuals who are at risk for depression.”

Heart Health

Studies have found that individuals with obesity and high blood pressure tend to have lower vitamin D levels. Some research stated that the vitamin can help lower blood pressure. There are some studies that have shown that it lowers the risk of stroke and heart attack.

Weight Loss

There was a study done where postmenopausal women were given vitamin D3 supplements (compared with a placebo) for a weight loss intervention. The outcome showed that the women who had adequate levels of vitamin D3 lost more body fat, saw a greater reduction in waist circumference, and lost more weight.

Suggested Doses

Unless you are in an area that has a forecast of sunny skies more often than not, it is difficult to get the suggested dose of vitamin D3 naturally through food and the sun. The Medical and Health Division increased the RDA for vitamin D to 600 IU for people up to age 70 and 800 IU for those over 70.

The safe upper limit of daily intake for most age groups was also raised from 2,000 to 4,000 IU. A blood test will let you know if you need additional vitamin D3. You can get supplements and this should be discussed with your medical provider.

Vitamin D3 Deficiency

Research shows that over 1 billion people have a vitamin D deficiency overall. Symptoms and associated conditions include muscle weakness and aches, weak bones, fatigue, hair loss, depression, hypertension, inflammation, arthritis, and eczema just to name a few.

Risks

Vitamin D3 is generally safe. If you take too much vitamin D3 some overdose symptoms include nausea, vomiting, mood changes, constipation, dizziness, loss of appetite, dehydration, and constipation.

A Word From Verywell

Vitamin D3 is an essential nutrient in the human diet. It's critical for the development and normal functioning of many organs in the body. You should try to get your daily recommended intake of vitamin D3. Try to enjoy time in the sun as much as possible and eat foods that naturally have vitamin D3.

If you are not sure if you have enough vitamin D talk to your doctor about getting a blood test and supplements. As with most other vitamins and nutrients, it may be best to get your daily requirements from food sources. If you need additional supplements, contact a healthcare professional.  

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