What it is: Vitamin D3, or cholecalciferol, is a fat-soluble vitamin that the human body produces when skin is exposed to ultraviolet B (UVB) sunlight. It is the most active and absorbable form of vitamin D found in humans.
What it does: Vitamin D3 supports the absorption of calcium and phosphorus from food, which is essential for building and maintaining healthy bones and teeth. It also plays a key role in immune system regulation and muscle function.
How it is used: Vitamin D3 is often taken to promote bone health, support immune defenses, aid in calcium balance, and help prevent deficiency in people who get little sunlight, as well as those at risk for low vitamin D levels.
Natural sources and supplement forms: Natural sources include skin synthesis from sunlight, oily fish like salmon and mackerel, cod liver oil, egg yolks, and fortified foods such as dairy or plant milks. Supplements commonly provide D3 as cholecalciferol in softgels, tablets, or liquid drops.
Why it appears in supplement formulas: Vitamin D3 is included to help maintain adequate blood levels of vitamin D, especially for individuals with limited sun exposure or diets lacking in natural sources. This helps support bone, immune, and overall wellness.
What to know before use: Taking too much vitamin D3 over time may increase the risk of high blood calcium levels; consult a healthcare provider if you have medical conditions or take medications affecting calcium metabolism.
What it does: Vitamin D3 supports the absorption of calcium and phosphorus from food, which is essential for building and maintaining healthy bones and teeth. It also plays a key role in immune system regulation and muscle function.
How it is used: Vitamin D3 is often taken to promote bone health, support immune defenses, aid in calcium balance, and help prevent deficiency in people who get little sunlight, as well as those at risk for low vitamin D levels.
Natural sources and supplement forms: Natural sources include skin synthesis from sunlight, oily fish like salmon and mackerel, cod liver oil, egg yolks, and fortified foods such as dairy or plant milks. Supplements commonly provide D3 as cholecalciferol in softgels, tablets, or liquid drops.
Why it appears in supplement formulas: Vitamin D3 is included to help maintain adequate blood levels of vitamin D, especially for individuals with limited sun exposure or diets lacking in natural sources. This helps support bone, immune, and overall wellness.
What to know before use: Taking too much vitamin D3 over time may increase the risk of high blood calcium levels; consult a healthcare provider if you have medical conditions or take medications affecting calcium metabolism.
Interesting Fact
Vitamin D3: The Sunshine Nutrient Your Body Can Make
Vitamin D3 is unique among vitamins because your body can naturally produce it when your skin is exposed to sunlight. While some foods contain small amounts, such as fatty fish, eggs, and fortified milk, getting enough sun isn’t always easy—especially in winter or for those mostly indoors. This is why D3 is a common and important addition to many daily supplements.
