So as not to take up too much of your time today, I want to briefly draw your attention to the paper (personal view) from Jerome Sarris and colleagues  carrying the same title as that of this blog post: 'Nutritional medicine as mainstream in psychiatry' published in The Lancet Psychiatry.
Aside from applauding the notion that nutrition is potentially of some importance to "both physical and mental health" alongside that is, the value of exercise (see here for example), the important word to come from the Sarris paper is 'mainstream', denoting 'current thought of the majority' and distinct from 'fringe' or 'pseudo' science. The kinda of words I've heard quite a bit down the years of my research interest in this whole gluten- and casein-free diet for [some] autism malarkey.
Sarris already has some research form on, for example, the potentially beneficial role of multivitamins on mood and wellbeing  (open-access) so approaches this issue as a research insider rather than external commentator.
"Evidence is steadily growing for the relation between dietary quality (and potential nutritional deficiencies) and mental health, and for the select use of nutrient-based supplements to address deficiencies, or as monotherapies or augmentation therapies." I'd be minded to agree. I've covered this from a few angles on this blog, bearing in mind (a) no medical or clinical advice is given or intended and (b) the moves towards plurality in psychiatry (see here and see here) potentially also denotes the idea of best- and non-responders to various interventions:
- Vitamins and autism: double-blind, placebo-controlled RCT (December 2011)
- Psychosis, gluten and vitamin D (May 2012)
- Gliadin antibodies in schizophrenia replicated (January 2013)
- Folic-ing around in schizophrenia (March 2013)
- Vitamin-mineral mix for ADHD? (February 2014)
- Phenylalanine and schizophrenia: new directions for intervention? (April 2014)
- Vitamin D and depression / depressive symptoms (June 2014)
- Vitamin D and schizophrenia meta-analysed (August 2014)
- Omega-3 fatty acids and ADHD (September 2014)
And with that, enjoy your day with some Hot Chocolate. Oh, and do be careful if...
 Sarris J. et al. Nutritional medicine as mainstream in psychiatry. Lancet Psychiatry. 2015. January 25.
 Sarris J. et al. Participant experiences from chronic administration of a multivitamin versus placebo on subjective health and wellbeing: a double-blind qualitative analysis of a randomised controlled trial. Nutr J. 2012 Dec 14;11:110.
Jerome Sarris, Alan C Logan, Tasnime N Akbaraly, G Paul Amminger, Vicent Balanzá-Martínez, Marlene P Freeman, Joseph Hibbeln, Yutaka Matsuoka, David Mischoulon, Tetsuya Mizoue, Akiko Nanri, Daisuke Nishi, Drew Ramsey, Julia J Rucklidge, Almudena Sanchez-Villegas, Andrew Scholey, Kuan-Pin Su, & Felice N Jacka (2015). Nutritional medicine as mainstream in psychiatry Lancet Psychiatry : http://dx.doi.org/10.1016/S2215-0366(14)00051-0