In addition, certain dietary deficiencies have been linked (though, in most cases, not conclusively) to reduced energy and mood: Many of the B vitamins, particularly B6 (pyridoxine), B9 (folic acid), and B12 (cobalamin). Vitamin D (though it must be added that most of the body’s D is produced by sun exposure). Omega-3 fatty acids. The research isn’t firm on the matter, but it suggests a link between deficiency and lower mood. Iron. Deficiencies are most likely to appear in women, vegetarians, and athletes.
