Daily supplementation with a broad range of vitamins and minerals can provide nutritional insurance by helping to provide an optimum intake for the maintenance of good health. A Harvard review published in the Journal of the American Medical Association in 2002 recommended that all adults should take a multivitamin daily. Statistics suggest that many people are not consuming optimal amounts of vitamins in their diets. Low levels of vitamins can contribute to the development of a range of conditions.In addition recent studies have shown that the nutrient levels in fruits, vegetables and some food crops have declined in the past 50 years. This may be primarily due to the way food is grown, processed and prepared.