TFRC and nutritional disorder: However, the incidence of iron deficiency was significantly higher in women compared to men and in the oldest age group (80 + years) compared to the youngest group (70–74 years) when taking the other three definitions of iron deficiency (ferritin < 45 μg/L, ferritin < 30 μg/L, and sTfR–ferritin index > 1.5).