Synonyms for Vital:

adj.

alive (adjective)
live, living, animate.
all (adjective)
lively, critical.
critical (adjective)
crucial.
energetic (adjective)
red-blooded.
essential (adjective)
critical, meaningful, indispensable, requisite, fundamental, significant, necessary, constitutive, integral, important, basic, crucial.
existent (adjective)
live.
important (adjective)
major, central, meaningful, serious, significant, crucial.
live (adjective)
animate, alive, living, incarnate, organic, live.
lively (adjective)
lively, alert, mettlesome, enthusiastic, vigorous, active, red-blooded, lusty, brisk, animated, energetic.
meaningful (adjective)
significant.
strong (adjective)
brawny, virile, mighty, muscular, tough, stout, firm, powerful, stable, sinewy, husky, strong, vigorous, formidable, energetic, sturdy, robust, potent, mettlesome.
vigorous (adjective)
lusty.

n.

lusty, strapping, red-blooded, able-bodied, iron. be, integral, constitutional, basic, surface, fundamental, constitutive. fatal, mortal, lethal, deadly, deathly. necessary (noun)
necessary, contribute, without fail, of necessity, compulsory, requisite, important, at all costs, obligatory.
vital (noun)
animated, alive, essential, full of life, lively, life-sustaining, critical, indispensable.

Other synonyms:

fundamental, important, constitutive. lusty, strapping, red-blooded, able-bodied, lethal. deadly, basic, integral, deathly, iron, fatal. mortal. essential
necessary, essential.
necessary
obligatory, compulsory.
physical
constitutional.

Usage examples for vital

  1. Other details with regard to health reports will be found in the chapter on Vital Statistics. – Civics and Health by William H. Allen
  2. They are vital and have to be studied in a vital manner; experienced through and through, over and over again, so that each part of the nature has been penetrated by them. – Light On The Path and Through the Gates of Gold by Mabel Collins