Assessment of Nutrient Adequacy, Dietary Diversity Score, and Dietary Inflammatory Index in Individuals with Systemic Lupus Erythematosus (SLE)

Background Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disorder primarily affecting women of reproductive age and non-white populations. It arises from genetic and environmental interactions, leading to inflammation, tissue damage, and multi-organ involvement. Evidence suggests that poor nutrient intake, low dietary diversity, and pro-inflammatory diets influence disease activity, yet their combined impact on SLE risk remains unclear. This study aimed to assess the association between nutrient adequacy, dietary diversity, and the inflammatory potential of diet with SLE risk. Methodology: A case-control study included 400 women (150 SLE cases, 250 age-matched healthy controls) aged 15–45 years. Dietary intake was assessed using a validated semi-quantitative FFQ. Nutrient adequacy was evaluated via AMDR and the Probability of Adequacy for ten key micronutrients. Dietary Diversity Score (DDS) was calculated across ten food groups, and the Dietary Inflammatory Index (DII) was derived from 21 pro- and anti-inflammatory dietary parameters. Multivariate logistic regression examined associations of DDS, DII, and nutrient adequacy with SLE risk, adjusting for age, gender and BMI. Results SLE cases consumed significantly less energy (865 vs 1681 kcal), protein (24 vs 47 g), fat (23 vs 34 g), and carbohydrates (128 vs 223 g) than controls (all p  < 0.001). Fewer than 6% of cases met AMDR targets, and their mean probability of adequacy for micronutrients was ninefold lower, with notable deficiencies in B-complex vitamins (especially B12), zinc, iron, and folate. Their diets were also less diverse (Dietary Diversity Score, p  < 0.001) and more pro-inflammatory (Dietary Inflammatory Index). Each one-unit increase in DII raised SLE odds by 27%, while a 1% increase in MPA reduced odds by 14%. Conclusion Women with SLE exhibited dietary patterns that were micronutrient-deficient, less diverse, and highly pro-inflammatory. A higher Dietary Inflammatory Index (DII) score independently predicted the presence of SLE. These findings highlight the critical role of dietary assessment and targeted nutritional interventions as adjuncts in the clinical management of SLE.