Deficiency of vitamins has serious consequences. Lack of vitamin A leads to night blindness, retarded growth of the skeleton and problems of the skin and gastrointestinal tract. Vitamin B1 deficiency causes leg cramps, muscular weakness, irritability and digestive problems. Mouth ulcers, inflammation of the tongue, weakness, low blood counts and dandruff are among the symptoms of lack of vitamin B2. Insufficient vitamin B3 causes pellagra, while a deficiency of vitamin B6 leads to skin problems, mental confusion and lowered immunity. Vitamin B5 is an antioxidant required for growth, reproduction and bodily processes, so a lack of it produces heart problems and depression. Inadequate vitamin B12 causes pernicious anemia, while scurvy and rickets are the main symptoms of a lack of vitamins C and D respectively. Vitamin E deficiency affects the nervous system and leads to weakness, vision related problems and loss of muscle mass. Finally, easy bruising and gastrointestinal bleeding are symptoms of vitamin K deficiency.
It is important to be aware of the multiple functions of vitamins and effects of deficiencies to understand the role of vitamin supplements. Vitamins allow nutrients to be digested and absorbed and convert carbohydrates and fats into energy. They help to metabolize nutrients, produce antibodies to strengthen immunity and develop resistance to diseases. Vitamins strengthen cells, bind tissues, form bones, blood cells and genetic material, hormones and chemicals of the nervous system and combine with proteins to produce enzymes. Each group of vitamins performs more specific roles.
Since deficiencies can lead to multiple health problems, it is essential to include all the vitamins in the diet. The RDA or Recommended Dietary Allowance for vitamins has been set by the Food and Nutrition Board of the National Academy of Sciences and National Research Council. It is the average daily nutrient intake level sufficient for nutrient requirements of most (97%-98%) healthy individuals in particular gender and stage of life. However, since nutrients may be missing from the diet, supplements are prescribed to fill the gap.
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