Even with dietary supplements, large proportions of US adults have micronutrient intakes below the Estimated Average Requirement. Adults at the highest adjusted income have higher micronutrient intakes and lower risk of inadequacy than those with lower incomes.

Fiber has been identified as both a ‘shortfall nutrient’ and a ‘nutrient of public health concern.’ However, little is known about dietary fiber intake relative to poverty-income ratio (PIR) and race/ethnicity in US adults. We examined usual intakes of dietary fiber and compliance with the adequate intake (AI) in US adults (≥19 years) using National Health and Nutrition Examination Survey 2011 to 2012 by PIR and race/ethnicity. Among both men and women, significantly higher fiber intake was observed among those in the highest PIR category (men, 22 [SE, 0.8]; women, 18 [SE, 0.6]) compared with those in the lowest category (men, 20 [SE, 0.7]; women, 15 [SE, 0.4]) and the middle category (men, 19 [SE, 0.7]; women, 15 [SE, 0.6]). Although men had higher intake of fiber across all PIR and race/ethnic groups, women had higher prevalence of intake above the AI. Among men, non-Hispanic blacks (17 [SE, 0.8]) had significantly lower intake; whereas among women non-Hispanic blacks (14 [SE, 0.4]) and Hispanic and Mexican Americans (16 [SE. 0.8]) had significantly lower intake compared with the other race/ethnic groups. Asian American women have the highest likelihood of fiber intake that exceeds the AI recommendation. Overall, fiber intake of US adults remains below federal recommendations. Systematic differences in fiber intake occur by PIR and race. Therefore, it is particularly salient to target intervention and education efforts to increase intake of dietary fiber in these groups.