how is vit d absorbed

Vitamin D is absorbed in the small intestine. Specifically, it is absorbed in the upper part of the small intestine, known as the duodenum and jejunum.

When we consume foods that contain vitamin D or take supplements, the vitamin D is first broken down in the stomach and then transported to the small intestine. In the small intestine, vitamin D is absorbed into the bloodstream through the intestinal lining.

Vitamin D can also be synthesized in the skin when it is exposed to sunlight. UVB radiation from the sun triggers a reaction in the skin that produces vitamin D3, which is then converted to its active form by the liver and kidneys.

Once in the bloodstream, vitamin D is transported to various tissues throughout the body where it is used for a variety of functions, such as maintaining bone health, supporting the immune system, and regulating cell growth and differentiation.