ABSTRACT
The preceding chapters discussed macronutrients (carbohydrates, lipids, and proteins), which provide energy and substrates for constant rebuilding of the middleaged body, as required by an active lifestyle. Humans also need many micronutrients in their diet, and an adequate supply of vitamins and minerals may be of crucial importance in affluent Western societies, where the abundance of high-calorie food causes a high prevalence of obesity and various health problems of middle age.1 The diet of 30-60 year-old-people should not be energy-dense, but rich in micronutrients and fiber, which is optimal for our species. Humans evolved as hunters-gatherers, omnivores consuming meat, seafood, and plants (various fruits, vegetables, seeds, and nuts). With the introduction of agriculture, only about 12,000 years ago, starchy grains and tubers became the basis of the human diet, with a corresponding decline in the health of human populations.2 Progressive developments in nutrition and medicine identified many important micronutrients and their role in maintaining health. Among them, the fat-soluble vitamins are distinguished by physical properties associated with low polarity, absorption requiring the presence of fat, specific transport modes, accumulation in the liver, adipose, and certain other tissues. While adequate intake of fat-soluble vitamins is undoubtedly necessary over the life span, the body can store enough of these micronutrients to prevent deficiency during long periods of low intake. On the other hand, excessive intake of vitamins A and D may result in dangerous toxicity.
