A low hematocrit level may mean the patient is malnourished, anemic, overhydrated or bleeding, according to MedlinePlus. A low hematocrit level may also be due to nutritional deficiencies, leukemia or the destruction of red blood cells.
Deficiencies of folate, vitamin B12, iron and vitamin B6 may cause a low hematocrit level, explains MedlinePlus. Normal hematocrit levels generally range from 40.7 to 50.3 percent for men and from 36.1 to 44.3 percent for women, though results vary depending on the laboratory. A typical range for children is 45 to 61 percent for newborns and 32 to 42 percent for infants.
Hematocrit blood tests measure the percentage of the volume of whole blood that is composed of red blood cells, according to MedlinePlus. The number and size of the red blood cells influence the measurement.