Vetafarm True Grit Fine. Vetafarm True Grit is a vitamin and mineral enriched shell grit for the addition to seed diets. True Grit is a good source of vitamins, minerals and calcium and is recommended for birds on seed diets in conjunction with other supplements. Vetafarm True Grit contains a mixture of vitamins, minerals and calcium and aids in the digestion of food. It is a good general supplement to be added to a bird’s environment as a ‘free choice’. Breeding birds on seed diets in particular can benefit from the supplement during the nutritionally demanding period. Grit sizes – Fine: For small to medium passerines and parrots; Medium: For large parrots and pigeons.