Vitamin D, From the Sun?

Early morning exercise and staying under the morning sun were just few of the advises we got from our elementary mentors. We were taught that such activities help us get vitamin D from the sun.

Does vitamin D really comes from the sun? Truth is, the only particle that the sunlight carries are photons and I don’t think that vitamin D is made up of these photons.

Vitamin D, is a group fat soluble secosteroid, which means a form of steroid, that is derived from cholesterol. Vitamin D3, for instance, is made in the skin when 7-dehydrocholesterol (a form of cholesterol in skin) reacts with ultraviolet light (UVB) at wavelengths between 270 and 300 nm, with peak synthesis occurring between 295 and 297 nm. The ultraviolet rays penetrates the skin, reaches stratum spinosum and stratum basale, the cholesterol-rich layer of the skin, and photolyzed the cholesterol. The process is called 6-electron conrotatory electrocyclic reaction and the product is pre-vitamin D3. Previtamin D3 spontaneously isomerizes to vitamin D3 (cholecalciferol) in a biochemical process called antarafacial sigmatropic [1,7] hydride shift. At room temperature, the transformation of pre-vitamin D3 to vitamin D3 takes about 12 days to complete.

Other forms of vitamin D includes Vitamin D1 (a molecular compound of ergocalciferol with lumisterol), Vitamin D2 (or ergocalciferol which is made from ergosterol, a cholesterol found in fungi e.g. mushroom), Vitamin D4 (22-dihydroergocalciferol), and vitamin D5 (sitocalciferol).

Vitamin D is essential to humans. After being synthesized by the kidney, it circulates as a hormone, regulating the concentration of calcium and phosphate in the bloodstream, promoting the healthy mineralization, growth and remodeling of bone, and the prevention of hypocalcemic tetany. Together with calcium, vitamin D helps to protect older adults from osteoporosis.

Vitamin D deficiency, on the other hand could result to Rickets, a childhood disease characterized by impeded growth and deformity of the long bones, and Osteomalacia, a bone-thinning disorder that occurs exclusively in adults and is characterized by proximal muscle weakness and bone fragility.

And this is good thing to note that taking calcium without vitamin D will just result to gall bladder stones.

Vitamin D has long been believed to come from the sun and the real score has not been told to the younger individuals. Maybe because of the complicated process it take to make vitamin D? But why photosynthesis is being taught where it almost undergoes the same process, I mean, both processes uses ultraviolet rays to proceed?

Anyways, that is so much for debate, my purpose is just to share.