add on, addendum, appurtenance, accessory, affix, postscript, append, supplemental, supplementary, augment, more...

reduce, decrease, diminish, subtract, lessen

protein, vitamin, mineral, herbal, nutritional, more...

special, dietary, useful, valuable, important, annual, necessary, nutritional, second, literary, daily

adding on,   adds on,   to add to,   to add on,   add to,   add on to,   adding on to,   additional amount,   chemical addition,   add onto