Which is the normal range of gamma gt for an african american woman? (ui/l).thanks

Hard to say: Until age 60, GGT tends to increase as the years go by, faster in men than in women. At any age and for any level of drinking, it's about twice as high in african-americans. This makes for unfair situations as GGT is often used as a screen to see if someone is secretly abusing alcohol. If my GGT were above 100 regardless of who i was, i would wonder; however, it's a poor screen for disease.