Volume 30, Issue 175, September 2026

The Role of Selected Dietary Supplements (Vitamin D, Creatine, Folic Acid, and Omega-3 Fatty Acids) in the Management of Depressive Disorders: A Narrative Review

Zuzanna Knap^♦, Marcelina Zielińska, Przemysław Iwański, Julia Kałużna, Ali Kraziński, Julia Mrowińska, Aleksandra Mazur, Natalia Grzywacz, Iga Chalimoniuk, Anna Hejman

Poznan University of Medical Sciences, Poznan, Poland

^♦Corresponding author
Zuzanna Knap, Poznan University of Medical Sciences, Poznan, Poland

ABSTRACT

Depression is one of the most disabling conditions in the world, and many patients do not achieve full remission with standard treatments. There has been increasing interest in dietary supplements as potential adjuncts to standard treatments for depression. This narrative review examines the evidence regarding vitamin D, creatine, folic acid and omega-3 fatty acids in depressive disorders, with a focus on their potential use alongside standard treatment. A search of PubMed and Google Scholar was performed to identify meta-analyses, systematic reviews and randomised controlled trials evaluating these supplements in the treatment of depression. All four supplements examined have been associated with reductions in depressive symptoms. Vitamin D and omega-3 fatty acids have shown benefits in people with depressive disorders, while folic acid may be beneficial as an adjunct to antidepressants in people with low folate levels. Creatine has also shown some benefits in people taking antidepressants or undergoing cognitive behavioural therapy, although results are not yet conclusive. These findings suggest that dietary supplements could play a role in the treatment of depression, albeit as an adjunct to antidepressant medication. Further studies are required to determine optimal dosing and treatment duration, as well as the patient populations most likely to benefit.

Keywords: Supplementation, vitamin D, creatine, folic acid, omega-3 fatty acids, depression, depressive symptoms

Medical Science, 2026, 30, e186ms3972

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DOI: https://doi.org/10.54905/disssi.v30i175.e186ms3972

Published: 15 September 2026