Vitamin D is a unique fat-soluble vitamin that's often called the “sunshine vitamin” because it is naturally produced by the cholesterol in your skin cells when your skin is exposed to sunlight.
The sun's ultraviolet B (UVB) rays interact with the cholesterol, providing the energy for vitamin D synthesis to occur. Skin that has more melanin tends to block UVB rays which facilitate the production of vitamin D in the skin. This is why people with darker skin pigmentation are at higher risk of vitamin D deficiency.
As an essential vitamin, vitamin D plays vital roles throughout your body to keep you strong and healthy. Some of the many health benefits it provides include supporting healthy bone, brain, and immune system function, as well as uplifting your mood.
There are 2 types of vitamin D: D2 and D3. Vitamin D3 is generally regarded as superior, since it is the form that most closely resembles the one your body naturally produces. You can increase your vitamin D intake by eating foods that are rich in vitamin D and by taking vitamin D3 supplements.