Comparison of proposed definitions of lower limit of normal blood haemoglobin concentration.

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)	13^*	12.8	12.7	11.2^***
White women (g/dL)	13^>12^	12.2	12.2	13^>11.3^**
Black women (g/dL)	13^>12^	11.3	11.5	13^>11.3^**

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].