A risk-based approach to measuring population micronutrient status from blood biomarker concentrations

Nutrient biomarkers and their definitive cut-offs are used to classify individuals as nutrient-deficient or sufficient. This determinism does not consider any uncertainty, and a probability approach, using biomarker distributions, is then preferable to define the risk of nutrition deficiency when in populations.

Healthy 1-19-year-old children and adolescents were selected from the Comprehensive National Nutrition Survey (CNNS), to obtain probability distributions of their retinol, zinc and vitamin B₁₂, along with erythrocyte folate. Model-based estimates of location, scale and shape parameters of these distributions were obtained across ages. Subsequently, in the entire sample of 1-19 year old children of CNNS, the population risk of deficiency (PRD) which is average risk of deficiency in individuals in the population was computed, which is "of concern" when >50%. When individual risk of deficiency is >97.5% it is called "severe risk of deficiency" (SRD).

In the entire CNNS sample, the PRD of concern was low for serum retinol (3.6-8.2%), zinc (0-5.5%), and SRD of vitamin B₁₂ and erythrocyte folate were 2.3-7.2% and 4.2-9.7%, respectively, across age and sex groups.

This proposed method assesses the adequacy of nutrient exposures without relying on pre-defined deterministic biomarker cut-offs to define micronutrient deficiency and avoids errors in exposure assessment.