Table 3: Comparison of proposed definitions of lower limit of normal blood haemoglobin concentration.

Population WHO(1968) NHANES III(1994) NHANES III(1994) Present study(2016)
White men (g/dL) 13* 13.8** 13.2*** 11.2***
Black men (g/dL) 12.8 12.7
White women (g/dL) 13*>12* 12.2 12.2 13*>11.3***
Black women (g/dL) 11.3 11.5

NHANES III = Third US National Health and Nutrition Examination Survey; NRS = not reported separately; WHO = World Health Organisation.

*WHO numbers did not distinguish normal levels based on age or racial differences; **Values in this column refer to the lowest 5% of actual NHANES III population distribution. The 5% threshold for the normal Gaussian distribution differs by less than 0.2 g/dL in each group; ***Proposed range for the group aged 60 years and older, also based on the 5% actual distribution in the population; ****Present study numbers does not distinguish racial differences due to the multi-ethnicity of the Brazilian population. Data from references [10,15,22].