how to combat vitamin deficiency in a natural way avoiding tablets?

For long I have wondered why we take so many vitamin tablets when our body can absorb only very less of it.
Vitamin B1 or thiamine deficiency can be overcome by taking rice waterwash with a pinch of salt.
Vitamin C by taking Lime juice with salt
Vitamin D by simply standing for some time in morning sun
Vitamin A by taking carrot  in empty stomach or carrot juice with a spoon of milk

In general we can get intake of all vitamins by including greens veg and fruits