Vitamin D
Vitamin D, also known as "calciferol," is a fat-soluble vitamin that is naturally present in a few foods, added to others, and available as a dietary supplement. It is essential for promoting calcium absorption in the gut, maintaining adequate serum calcium and phosphate concentrations, enabling normal bone mineralization, and preventing conditions such as rickets in children and osteomalacia in adults. Together with calcium, vitamin D also helps protect older adults from osteoporosis. Additionally, vitamin D has other roles in the body, including reducing inflammation, modulating cell growth, neuromuscular and immune function, and glucose metabolism.
Vitamin D can be obtained from sun exposure, foods, and supplements. It is produced endogenously when ultraviolet (UV) rays from sunlight strike the skin and trigger vitamin D synthesis. Fortified foods, such as milk, breakfast cereals, orange juice, yogurt, and margarine, provide most of the vitamin D in the diets of people in the United States. Fatty fish, fish liver oils, beef liver, egg yolks, and cheese are among the best natural sources of vitamin D. Additionally, vitamin D supplements are available in two forms: D2 (ergocalciferol) and D3 (cholecalciferol), with D3 being more potent at raising vitamin D levels in the blood.
Vitamin D is crucial for building and maintaining healthy bones, as it helps the body absorb calcium, the primary component of bones. It also plays a role in the nerve, muscle, and immune systems. However, its important to be mindful of sun exposure, as too much sun can lead to skin aging and skin cancer. Therefore, many people try to get their vitamin D from other sources, such as diet and supplements.
In summary, vitamin D is a vital nutrient that supports bone health, calcium absorption, and various other physiological functions in the body. It can be obtained from sunlight, certain foods, and supplements, and its importance in maintaining overall health cannot be overstated.
