what dose dietary supplement mean ??

Answer 1

That which supplements your diet. Protein supplements, vitamin and mineral supplements etc.

Answer 2

That's probably the recommended dosage by the dietary supplement manufacturer.

Answer 3

Extra vitamins taken (usually tablet form), to increase intake, of certain nutrients, especially [but not always] for someone dieting who may not be eating foods rich in vitamins - or enough of them - due to consuming less. Also for anyone needing extra vitamins which may be necessary for their particular needs, i.e. a woman needing more B12 vitamin at that time of the month.