Vitamin D and mental health: what the evidence really says
Vitamin D and mental health: what the evidence really says Written by: Therapy Near Me Editorial Team Clinically reviewed by: qualified members of the Therapy Near Me clinical team Last updated: 20/12/2025 This article is intended as general information only and does not replace personalised medical or mental health advice. Learn more about our Editorial Policy. By TherapyNearMe.com.au. General information only; not a substitute for personal medical advice. If you have concerning mood symptoms, speak with your GP or a registered psychologist. For urgent help, call 000; 24/7 support: Lifeline 13 11 14; Beyond Blue 1300 22 4636. Key points at a glance What vitamin D is (and why the brain cares) Vitamin D is a secosteroid hormone. After skin UV‑B exposure or intake from diet/supplements, it is hydroxylated in the liver to 25‑hydroxyvitamin D [25(OH)D], then in kidneys and other tissues (including brain and immune cells) to 1,25‑dihydroxyvitamin D, the active form. Vitamin D receptors (VDR) and 1‑alpha‑hydroxylase are expressed in neurons, glia and endothelial cells, suggesting roles in neurodevelopment, neuroimmune modulation, calcium signalling, and neurotransmission (Eyles et al., 2013). Depression: what do the best studies show? Observational links Large cohorts show that lower 25(OH)D correlates with higher depressive symptoms scores and incident depression, particularly in older adults and those with chronic illness (Anglin et al., 2013). Correlation, however, is not causation: low vitamin D may be a marker of ill‑health, low outdoor activity, or poor diet. Randomised trials and meta‑analyses Bottom line: For most people, vitamin D alone is unlikely to prevent or treat depression. If you are deficient, correcting deficiency may support overall health and could augment standard treatments. Anxiety, psychosis, and cognition: what we know Seasonal mood and light: is vitamin D the lever? Winter low mood in higher latitudes is more strongly improved by bright‑light therapy than by vitamin D supplements; evidence that vitamin D alone treats seasonal affective patterns is weak (Lam et al., 2016). Light affects circadian systems directly; vitamin D may be a parallel marker of reduced outdoor exposure rather than the primary driver. Testing, targets and who is at risk (Australia) Sunlight vs supplements in Australia: finding the balance Safety note: High vitamin D can cause hypercalcaemia (nausea, confusion, arrhythmias). Extra caution is needed in conditions like sarcoidosis or with thiazide diuretics—seek medical advice. Where vitamin D fits in a whole‑person mental‑health plan Common myths Practical Q&A Should I take vitamin D if I feel depressed?Talk to your GP first. If you are at risk of deficiency, testing and replacement may help your overall health while you start first‑line treatments for depression. Can sunlight alone fix low vitamin D?Sometimes, depending on your location, season, skin type and habits. In winter or for people who avoid sun for medical/cultural reasons, supplements are often needed (Cancer Council Australia/ACD, 2023). How long until levels improve?With daily dosing (e.g., 1,000 IU), 25(OH)D typically rises over 8–12 weeks; your clinician may re‑check levels and adjust. References Anglin, R.E.S., Samaan, Z., Walter, S.D. and McDonald, S.D. (2013) ‘Vitamin D deficiency and depression in adults: systematic review and meta‑analysis’, British Journal of Psychiatry, 202(2), pp. 100–107. Cancer Council Australia and Australasian College of Dermatologists (ACD) (2023) Position statement: Sun exposure and vitamin D. Sydney: Cancer Council Australia/ACD. Cuijpers, P., Karyotaki, E., Reijnders, M., Purgato, M. and Barth, J. (2017) ‘Psychotherapies for depression: A meta‑analysis’, CNS Spectrums, 22(4), pp. 324–332. DoHAC (Department of Health and Aged Care) (2024) ‘Vitamin D—consumer information’. Canberra: Australian Government. Available at: https://www.health.gov.au. Eyles, D.W., Burne, T.H.J. and McGrath, J.J. (2013) ‘Vitamin D in fetal brain development: evidence, mechanisms and implications’, Trends in Neurosciences, 36(5), pp. 295–302. FSANZ (Food Standards Australia New Zealand) (2022) ‘Nutrient tables and food composition: Vitamin D’. Canberra: FSANZ. Goodwill, A.M. and Szoeke, C. (2017) ‘A systematic review and meta‑analysis of the effect of low vitamin D on cognition’, Journal of the American Geriatrics Society, 65(10), pp. 2161–2168. IOM (Institute of Medicine) (2011) Dietary Reference Intakes for Calcium and Vitamin D. Washington, DC: National Academies Press. Lam, R.W., Levitt, A.J., Levitan, R.D., Michalak, E.E., Cheung, A.H., Morehouse, R. and Tam, E.M. (2016) ‘Efficacy of bright light treatment for seasonal affective disorder’, Canadian Journal of Psychiatry, 61(1), pp. 14–23. McGrath, J.J., Eyles, D.W., Pedersen, C.B., Anderson, C., Ko, P., Burne, T.H.J., Nørgaard‑Pedersen, B., Hougaard, D.M., Mortensen, P.B. and Nielssen, O. (2010) ‘Neonatal vitamin D status and risk of schizophrenia: a population‑based case‑control study’, Archives of General Psychiatry, 67(9), pp. 889–894. NICE (National Institute for Health and Care Excellence) (2011) Generalised anxiety disorder and panic disorder in adults (CG113). London: NICE. NICE (2018) Depression in adults: treatment and management (NG222). London: NICE. Okereke, O.I., Reynor, K., Chang, S.C., Cook, N.R., Manson, J.E. and Buring, J.E. (2020) ‘Effect of long‑term vitamin D3 supplementation vs placebo on risk of depression or clinically relevant depressive symptoms’, JAMA, 324(5), pp. 471–480. RACGP (Royal Australian College of General Practitioners) (2018) Guidelines for preventive activities in general practice — Vitamin D testing and deficiency. Melbourne: RACGP. Sanders, K.M., Stuart, A.L., Williamson, E.J., Simpson, J.A., Kotowicz, M.A., Young, D. and Nicholson, G.C. (2010) ‘Annual high‑dose oral vitamin D and falls and fractures in older women’, JAMA, 303(18), pp. 1815–1822. Sarris, J., et al. (2021) ‘Adjunctive nutraceuticals for anxiety disorders: systematic review and meta‑analysis’, World Journal of Biological Psychiatry, 22(7), pp. 493–507. Shaffer, J.A., Edmondson, D., Wasson, L.T., Falzon, L., Homma, K., Ezeokoli, N., Li, P. and Davidson, K.W. (2014) ‘Vitamin D supplementation for depressive symptoms’, Psychosomatic Medicine, 76(3), pp. 190–196. White, R.L., et al. (2024) ‘A systematic observation of moderate‑to‑vigorous physical activity in blue spaces’, Health Promotion International, 39(4), daae101. Vellekkatt, F.I. and Menon, V. (2019) ‘Efficacy of vitamin D supplementation in major depression’, Journal of Postgraduate Medicine, 65(2), pp. 74–80. How to cite this article Therapy Near Me (2025) ‘Vitamin D and mental health: what the evidence really says’. Available at: https://TherapyNearMe.com.au (Accessed 9 December 2025).
Vitamin D and mental health: what the evidence really says Read More »













