TABLE 4.
Terminology and definitions of population-level micronutrient deficiency status commonly used in the field of nutrition research compared with the GBD Study1
| Terminology | Nutritionists’ definition | Summary of indicators and modeling approach used in the GBD Study |
|---|---|---|
| Iodine deficiency | Concentrations of urinary iodine or thyroglobulin below or above the cutoff, respectively; prevalence of total goiter (palpable, but not visible; and visible) (34–36) | Visible goiter |
| Anemia | Hemoglobin concentration cutoff specific to each population subgroup (as defined by age, sex, and physiological status) (67) | Hemoglobin concentration below the population-specific cutoff (67) |
| Dietary iron deficiency | Usual intake of iron from diet less than the population-specific EAR, as determined by dietary assessments, such as 24-h recalls | Risk exposure for dietary iron deficiency modeled based on hemoglobin concentration below the anemia cutoff after accounting for other known anemia causes, and after accounting for known causes of iron deficiency (such as hookworm, schistosomiasis, upper gastrointestinal bleeding, and gynecologic conditions) |
| Iron deficiency | Concentration of iron status biomarkers below (i.e., ferritin) or above (i.e., transferrin receptor, zinc protoporphyrin) the cutoff (38, 39); indicators commonly adjusted for indicators of inflammation (i.e., C-reactive protein, α-1-acid glycoprotein) (47, 48) | Risk exposure for iron deficiency modeled based on hemoglobin concentration below the anemia cutoff after accounting for other known anemia causes |
| Zinc deficiency | Concentration of plasma zinc below the population-specific cutoff (41); plasma zinc commonly adjusted for indicators of inflammation (i.e., C-reactive protein, α-1-acid glycoprotein), especially in young children (49) | Dietary zinc inadequacy estimated from dietary surveys and FAO SUAs, especially in young children |
| Vitamin A deficiency | Concentration of retinol or retinol-binding protein below the cutoff (45); concentrations often adjusted for indicators of inflammation (i.e., C-reactive protein, α-1-acid glycoprotein) (50) | Concentration of serum retinol below the cutoff |
1
EAR, estimated average requirement; GBD, Global Burden of Disease; SUA, Supply Utilization Account.