Calcium source for chicken

[deepakdavid90]

is the sand right kind of thing for chickens to eat for calcium sppliement?
I gave them with white marble grit?

 

[Fred's Hens]

The purpose of grit, which can be crushed granite, pebbles and sand they find themselves or provided by the owner, is to be used in the chicken's digestive tract to grind their food. Chicken's don't have teeth.

Calcium, which is needed only by laying hens to form egg shells, is not derived from the grit/sand/granite. Calcium comes from either a layer feed formula with added calcium or from feeding back egg shells, providing oyster shells and naturally from many food items which contain calcium.