The Total Nutrient Index is a useful measure for assessing total micronutrient exposures among U.S. Adults.

Publisher:
Oxford University Press (OUP)
Publication Type:
Journal Article
Citation:
Journal of Nutrition, 2022, 152, (3), pp. 863-871
Issue Date:
2022-01-01
Full metadata record
BACKGROUND: Most dietary indices reflect foods and beverages and do not include exposures from dietary supplements (DS) that provide substantial amounts of micronutrients. A nutrient-based approach that captures total intake inclusive of DS can strengthen exposure assessment. OBJECTIVE: To examine the construct and criterion validity of the Total Nutrient Index (TNI) among U.S. adults (≥19y; non-pregnant or lactating). METHODS: The TNI includes eight under-consumed micronutrients identified by the Dietary Guidelines for Americans: calcium; magnesium; potassium; choline; and vitamins A, C, D, and E. The TNI is expressed as a percentage of the Recommended Dietary Allowance or Adequate Intake to compute micronutrient component scores; the mean of the component scores yields the TNI score, ranging from 0-100. Data from exemplary menus and the 2003-2006 (≥19y; n = 8,861) and 2011-2014 NHANES (≥19y; n = 9,954) were employed. Exemplary menus were used to determine if the TNI yielded high scores from dietary sources (women 31-50y; men ≥70y). TNI scores were correlated with Healthy Eating Index (HEI)-2015 overall and component scores for dairy, fruits, and vegetables; TNI component scores for vitamins A, C, D, and E were correlated with respective biomarker data. TNI scores were compared between groups with known differences in nutrient intake based on the literature. RESULTS: The TNI yielded high scores on exemplary menus (84.8-93.3/100) and was moderately correlated (r = 0.48) with the HEI-2015. Mean TNI scores were significantly different for DS users (83.5) vs. non-users (67.1), non-smokers (76.8) vs. smokers (70.3), and those living with food security (76.6) vs. food insecurity (69.1). Correlations of TNI vitamin component scores with available biomarkers ranged from r = 0.12 (α-tocopherol) to r = 0.36 (serum 25(OH)D), and were significantly higher than correlations obtained from the diet alone. CONCLUSION: The evaluation of validity supports that the TNI is a useful construct to assess total micronutrient exposures of under-consumed micronutrients among U.S. adults.
Please use this identifier to cite or link to this item: