Because vitamins give u protein and strength.
because of aliens
Each vitamin has an important role i.e Vitamin A in carrot helps sight at night, vitamin D in milk helps your bones, vitamin C in oranges helps your body to heal when you are cut, vitamin B in vegetables helps your body make protein and energy.
You need vitamin A for healthy eyesight and skin.
You may need more vitamin C when your immune system need a boost. If you are getting sick or suffering from allergies, your body can use some extra vitamin C.
Vitamin K is a fat-soluble vitamin produced by bacteria in the GI tract. In needs fat (lipids) to be absorbed by the intestines. You do not need to add extra Vitamin K.
Solar UV.
Because you need it to rape horney camels
No, takin extra vitamin is damaging to the body, your body will produce what it need when it needs it, eat veg and fruit daily to be healthy.
First and foremost, humans need calcium which is a mineral. It absorbs better when combined with vitamin D. You need vitamin C to help keep your immune system strong, vitamin A for your eyes, and vitamin B for your brain.
The only way to reduce vitamin D in the body is to stop intake of vitamin D.
vitamin D
Vitamin B12 is the only water-soluble vitamin that can be stored in the human body in large amounts, primarily in the liver. This allows for a reserve to be maintained for months to years, unlike other water-soluble vitamins that need to be consumed more regularly.