Comprehensive Assessment of Adequate Nutrition in Children and Adults with Sickle Cell Disease As Determined By Dietary Guidelines for Americans

Background: Increasing evidence shows that adequate and balanced consumption of vital nutrients in the daily diet plays a role in promoting health and may alter the pathogenesis and progression of many diseases. Systematic nutrition assessment in individuals with sickle cell disease (SCD) is largely unexplored and thus it is not well understood how diet impacts SCD complications and health outcomes. Therefore, the objective of this study was to complete a systematic assessment of dietary nutrients consumed in individuals with SCD and determine how this consumption compares to national dietary recommendations.

Methods: We conducted a cross-sectional multi-site study of individuals with SCD ≥ 2 years. Dietary data were collected during routine clinic visits using the Food Screener (age 2-11.99 parent proxy, 12-17.99 self-report) and the Block Food and Activity Questionnaire (Block 2014 Adults) (age ≥18 years). The completed questionnaires were sent to the developers for quantification of nutrients that were used for further analysis. Dietary Guidelines for Americans 2020-2025 were used as our reference to determine whether individuals consumed the ‘adequate’ amount of specific macronutrients, minerals, and vitamins in their diet. Dietary Guidelines for Americans are a science-based resource published by the U.S. Departments of Agriculture and Health and Human Services that is focused on nutritional recommendations that promote health and reduce the risk of chronic diseases. These guidelines, updated every 5 years, include the recommended intake of macronutrients, minerals, and vitamins stratified by age and sex. We assessed nutrition for each study participant by determining if their reported intake of each nutrient met the recommended intake as per Dietary Guidelines for Americans based on their age and sex (designated yes/no). We then determined the proportion of individuals in the study cohort who achieved ‘adequate’ intake for each nutrient. We assessed a total of 21 nutrients: protein, carbohydrates, fiber, calcium, iron, magnesium, phosphate, potassium, sodium, zinc, thiamin, riboflavin, niacin, vitamin A, vitamin E, vitamin D, vitamin C, vitamin B6, vitamin B12, vitamin K, and folate equivalents. Descriptive statistics were used to assess the proportion of our combined cohort (children and adults) that consumed the ‘adequate’ amount of specific nutrients in their diet. We further describe the nutrients that were adequately consumed by 50% or more or less than 50% of the cohort.

Results: A total of 126 individuals with SCD were enrolled across the lifespan; 73% (n=92) were children ages 2-18 years, and 27% (n=34) were adults ages >18 years. Mean (SD) age for the entire study population was 15.3 (12.8) years; mean age for those 2-18 years was 8.6 (4.9) years and for those >18 was 33.2 (10.2) years. Of the entire study population, 46.8% (n=59) were female and distribution of genotype was HbSS 67.5%, HbSC 26.1%, HbSβ⁰thal 1.6%, and HbSβ⁺thal 4.8%. The following nutrients were consumed in adequate amounts by ≥50% of the study cohort; the exact proportion that met adequate consumption is in parentheses: protein (74.6%), carbohydrates (60.3%), sodium (57.1%), zinc (54.8%), thiamin (65.9%), riboflavin (72.2%) niacin (74.6%), vitamin B6 (75.4%), vitamin B12 (81.7%), vitamin K (52.4%), vitamin C (69%), and folate equivalents (60.3%). The following nutrients were consumed in adequate amounts by <50% of the study cohort: fiber (7.1%), calcium (21.4%), iron (46.8%), magnesium (31.7%), phosphate (48.4%), potassium (27.8%), vitamin A (33.3%), vitamin E (6.3%), and vitamin D (0.0%).

Conclusions: Data show that the consumption of key nutrients including those needed for adequate bone health such as calcium and vitamin D are lacking in a large proportion of individuals with SCD. These data suggest that targeted dietary counseling is needed for individuals with SCD to ensure adequate dietary consumption as per national recommendations. Further work is needed to compare reported nutrient consumption with objective measures of physiologic levels of macronutrients, minerals, and vitamins. Ultimately, future works should explore whether nutrition is associated with SCD-related complications and whether it could be a target for interventions.