General Knowledge - Basic General Knowledge - Discussion

Our bodies manufacture vitamin D when the sun's ultraviolet B (UVB) rays interact with 7-dehydrocholesterol (7-DHC) present in the skin.

"However, we can produce only a limited amount of vitamin D from UVB. A few minutes at midday are sufficient for many Caucasian".

Your body is able to produce its own vitamin D3 when your skin is exposed to the sun's ultraviolet rays, specifically ultraviolet (UVB) radiation. When UVB rays hit your skin, a chemical reaction happens: Your body begins the process of converting a prohormone in the skin into vitamin D. In this process, a form of cholesterol called 7-dehydrocholesterol (7-DHC), naturally found in your skin, absorbs the UVB radiation and gets converted into cholecalciferol. Cholecalciferol is the previtamin form of D3. Next, the previtamin travels through your bloodstream to your liver, where the body begins to metabolize it, turning it into hydroxyvitamin D, which is also known as 25-hydroxyvitamin D or 25(OH)D. The kidneys then convert the 25(OH)D into dihydroxyvitamin D, also called 1,25-dihydroxyvitamin D or 25(OH)2D -- this is the hormone form of vitamin D your body can use.

No we don't get vit D in the evening only in morning between seven to ten.

Is we get vitamin D at evening?

Is only at morning in low sunlight we get vitamin D or we get at any time in a day?

Why only morning sunrays? why not evening sunrays?

But in morning the uv is very low in sunlight so it is not harmful. , and only in morning we get Vit. D. Not all over the day.

If we don't have enough vitamin D in our body we may get diseases so the sunlight gives us vitamin D so sunlight is good.

Ozone layer protect us from the uv rays but in that days in many area like africa, west indies and many other places a hole is found in ozone layer it is affected by air of freeze, by our toothpaste, green house effect and by chlorofluorocarbon are responsible for it.

What are skin oils?can anybody explain this please?