Systematic review and meta-analysis of randomized placebo-controlled trials of folate and vitamin B12 for depression.

Oral folic acid and vitamin B-12 supplementation to prevent cognitive decline in community-dwelling older adults with depressive symptoms—the Beyond Ageing Project: a randomized controlled trial

Associations between body mass index and the prevalence of low micronutrient levels among US adults.

Vitamin B12 deficiency in patients undergoing bariatric surgery: preventive strategies and key recommendations