Effects of omega-3 fatty acid and vitamin D supplementation in cancer patients: a systematic review and comparative synthesis by type of neoplasm

Apaza Durand A.J.; Ruiton Ricra J.G.; Dora Moscoso J.M.; Alvarez Rios C. · Nutricion Clinica y Dietetica Hospitalaria (2026) · DOI: 10.12873/ncdh-123

Resumen

Introduction: Cancer is one of the leading causes of morbidity and mortality worldwide. Systemic inflammation and malnutrition associated with this disease negatively impact clinical prognosis and treatment response. In this context, omega-3 fatty acid and vitamin D supplementation has been proposed as a complementary nutritional strategy with potential anti-inflammatory and immunomodulatory effects. Objective: To evaluate the effects of omega-3 fatty acid and vitamin D supplementation on inflammatory markers, nutritional status, and clinical outcomes in cancer patients. Materials and Methods: A systematic review was conducted according to PRISMA 2020 guidelines and registered in PROSPERO (CRD420261361041). A search was performed in PubMed/MEDLINE, Scopus, Web of Science, Embase, and the Cochrane Library from the inception of each database until March 2026. Two independent reviewers selected studies and resolved discrepancies by consensus. Randomized controlled trials and systematic reviews in adult cancer patients were included. Risk of bias was assessed using the RoB 2 tool. Results: Nine hundred records were identified, and 14 studies were ultimately included (9 randomized controlled trials and 5 systematic reviews/meta-analyses). Eight of the nine clinical trials reported improvement in at least one inflammatory or nutritional marker. Omega-3 and vitamin D supplementation was associated with reductions in C-reactive protein, interleukin-6, and tumor necrosis factor-alpha, as well as improvements in body weight, body mass index, and serum albumin, especially with co-supplementation. Results regarding tumor progression, cancer incidence, and mortality were heterogeneous and less consistent. Conclusions: The available evidence suggests that omega-3 and vitamin D supplementation may primarily contribute to reducing systemic inflammation and improving nutritional status in cancer patients. However, evidence on tumor progression, incidence, and mortality remains limited and heterogeneous.

Instituciones: Universidad Nacional Mayor de San Marcos; Universidad Andina del Cusco; Universidad Privada Norbert Wiener