Vitamins are necessary because they supplement those that the body excretes from time to time. They also help the body be healthy and the immune system boosted to fight off everyday infection from surroundings.
to keep you healthy
Vitamin K is the essential vitamin necessary for blood clotting.
Vitamin A
Vitamin A is necessary for night vision.
Vitamin A is necessary for good health. Eat your carrots.
Vitamin C
thrombase
Vitamin D is necessary for good function of brian. Javed Faysal 94
Vitamin D is produced by ultraviolet radiation on your skin. The UV light converts a precursor molecule to vitamin D.
Vitamin A is a vitamin that is needed by the retina of the eye in the form of a specific metabolite, the light-absorbing molecule retinal, that is necessary for both low-light and color vision.
"Intrisic factor" is necessary for B12 absorption
Of course you chikki Bastud
The likely word is "vitamin" (necessary metabolic compound).