# The Impact of Nutritional Status on Survival and Development of Sarcoidosis: A Scoping Review of Current Evidence and Research Gaps

## TL;DR

This review explores how nutrition, especially obesity and vitamin D, may affect sarcoidosis, a complex inflammatory disease, and highlights the need for better research.

## Contribution

The study maps current fragmented evidence on nutrition's role in sarcoidosis and identifies critical research gaps.

## Key findings

- Overweight and obesity are strongly linked to increased sarcoidosis risk and disease burden.
- Calcium–vitamin D metabolism disturbances are common and clinically relevant in sarcoidosis.
- Observational data suggest associations but lack evidence for causality or survival outcomes.

## Abstract

Background: Sarcoidosis is a heterogeneous, multisystem inflammatory disease with an unpredictable clinical course and limited prognostic markers. Increasing attention has focused on nutritional and metabolic factors—particularly obesity, body composition, and calcium–vitamin D metabolism—as potentially modifiable elements associated with disease development and clinical phenotype. However, the available literature remains fragmented and methodologically heterogeneous. Objective: To systematically map current evidence on the relationship between nutritional status and the development, clinical course, and prognosis of sarcoidosis, and to identify key gaps requiring further research. Methods: A scoping review was conducted in accordance with the Joanna Briggs Institute methodology and the PRISMA-ScR guidelines. PubMed, Scopus, Web of Science, Cochrane Library, EBSCO, and Google Scholar were searched for studies published between 2015 and 2025. Eligible studies included adult patients with sarcoidosis and addressed nutritional status broadly defined, encompassing anthropometric measures, body composition, immunonutritional indices, nutrition-related biomarkers, dietary factors, and supplementation practices. Due to substantial heterogeneity in exposure definitions and outcome measures, no quantitative synthesis or formal methodological quality appraisal was performed. Results: Eighteen studies, predominantly observational, were included. The most consistent findings concerned anthropometric parameters, with overweight and obesity showing the strongest association with an increased risk of sarcoidosis and, in selected studies, with reduced exercise capacity and greater disease burden. Evidence linking nutritional status to prognosis was indirect, while direct data on sarcoidosis-specific survival were lacking. Disturbances in calcium–vitamin D metabolism were frequent and clinically relevant, particularly in the context of supplementation-related hypercalcemia. Conclusions: Current evidence suggests that nutritional status—particularly excess body weight—and selected metabolic and immunonutritional factors are associated with sarcoidosis. However, given the largely observational nature of the available data and the lack of formal assessment of methodological quality, these results should be interpreted as association mapping and hypothesis generation rather than as evidence of causality. Well-designed prospective and interventional studies using standardized nutritional assessment tools and clinically relevant endpoints are needed to clarify the role of nutritional factors in sarcoidosis.