Table 2. Research evidence regarding the effects of specific nutrients and food components on schizophrenia.

References	Study design	Treatment	Main findings
[89]	Prospective, double-blind, placebo-controlled trial with 40 schizophrenia patients received atypical anti-psychotic drugs including olanzapine, quetiapine, and ziprasidone	500 mg/day of vitamin C for 8 wk	• Increase ascorbic acid levels and brief psychiatric rating scale scores
[91]	Randomized, double-blind controlled trial with 19 male schizophrenia patients	Resveratrol (200 mg/day) for 4 wk	• Decline in TG levels
[83]	Randomized, double-blind, placebo-controlled clinical trial with 47 schizophrenia patients who are prescribed with clozapine over 18 weeks, vitamin D levels < 75 nmol/L, and PANSS > 70	Oral vitamin D (14,000 IU) for 8 wk	• Increase the levels of vitamin D
			• Tend to improve cognitive function
			• No differences in psychotic, depressive or metabolic indicators
[86]	Randomized, double-blind, placebo-controlled trial with 60 schizophrenia patients with disease duration over 2 years, PANSS > 50, took chlorpromazine, anti-cholinergic medication at least 6 months	Vitamin D (50,000 IU) and 8 × 109 CFU/day of probiotics for 12 wk	• Improve PANSS scores
			• Reduce hs-CRP levels
			• Improve metabolic parameters (including fasting plasma glucose, insulin, and TG), and vitamin D levels

hs-CRP, high-sensitivity C-reactive protein; PANSS, Positive and Negative Syndrome Scale; TG, triglyceride.