An excellent mega-multivitamin. I take this when I've eaten enough iron, then take another multivitamin with iron when I haven't. The rationale for taking high levels of vitamins is the B.N. Ames hypothesis: during evolution, the metabolic energy pathways required to keep cells alive evolved to have higher affinities for the essential vitamins than other non-essential pathways such as those responsible for large molecule maintenance (DNA, collagen, etc). The reason is that keeping the cell alive is the highest priority -- even higher than maintenance. If the enzymes in the maintenance pathways would have high affinity for the same essential vitamins (which are used by hundreds of different pathways), during a food scarcity when vitamins are not available in the diet, the maintenance pathways would bind the vitamins and tend to prevent the essential metabolic pathways from functioning at full throttle, putting at risk the cell's survival. Therefore, the maintenance pathways generally have lower affinity for their required vitamins and don't function as well with low vitamin levels. This is good -- a life-saving property of the maintenance pathways. It is also the reason that higher levels of vitamins in a mega-multi-vitamin can be helpful in preventing progressive diseases associated with slow degradation of body tissues, such as heart disease, cancer, diabetes, eye problems.