Silica ok contains a balanced combination of nutrients in a single tablet the trace minerals selenium and zinc are included to help contribute to the maintenance of normal hair and nails also included in silica ok are key b vitamins such as b2 and biotin which play a role in the maintenance of normal skin as well as vitamin e which contributes to the protection of cells from oxidative stress vitamin c has been added to contribute to normal collagen formation collagen is a principle part of