A significant proportion of the general population report that they supplement their daily diet with one or more vitamins or minerals.  Common reasons given for doing so are to combat stress, reduce fatigue and improve mental functioning. This study looked at the effect of supplementing a range of essential nutrients on mood and cognitive function in 215 healthy males aged 30 to 55 years, who were in full-time employment.

The product used was a high dose B-complex, with 500mg of vitamin C plus the minerals calcium (100mg), magnesium (100mg) and zinc (10mg).  Many of these nutrients are in short supply in typical modern diets and all of them are known to be critical for optimal brain and central nervous system functioning. The participants received either placebo or the multi-vitamin/mineral supplement in identical effervescent tablets each morning for 1 month.

Before the study began all participants received a battery of tests designed to assess their self reported stress levels, and the mental fatigue that is induced by the continuous repetition of cognitively demanding tasks. The same tests were repeated at the end of the study and the effect of treatment on mood, mental fatigue, accuracy and speed of performance was assessed. The assessments were repeated  after a state of fatigue was induced, either by continuous repetition of a complex cognitive task or by physical activity.

At the end of the study the vitamin/mineral group rated themselves as less ‘mentally tired’ both before and after completion of the battery of cognitive tests. Supplementation led to improved ratings of stress, mental health and vigour, and improved performance under mental and physical stress. All the components in the active intervention were water soluble, and these essential nutrients therefore need to be replaced on a daily basis. B-vitamins, vitamin C, zinc and magnesium are also nutrients that are very vulnerable to depletion by stress.

Until now, studies evaluating the relationship between vitamin and mineral supplementation and psychological functioning have been in the sick or the elderly.  So it is refreshing to see such studies being carried out in younger, healthy individuals. The researchers conclude that healthy members of the general population may benefit from higher levels of vitamins and minerals through direct dietary supplementation.

Reference: Effects of high-dose B vitamin complex with vitamin C and minerals on subjective mood and performance in healthy males. Kennedy DO et al. Psychopharmacology (Berl). 2010 July; 211(1): 55–68.