Are nickel, vanadium, silicon, fluorine, and tin essential for man? A review.

“A trace element whose deficiency in experimental allimais requires unique environments and the preparation of special diets can hardly be of interest to human nutrition.” . . . “Nickel is so ubiquitous, it will never be of concern to tile human nutritionist.” . . . “Research with the ‘newer’ trace elements is of academic interest but of little relevance.” Investigators concerned witil tile role of the newer trace elements in nutrition often hear such opinions from colleagues with interests in other aspects of nutrition or metabolism. Such opinions may reflect a lack of appreciation of the fact tilat a short time ago zinc deficiency was thought to be an esoteric consideration as far as human nutrition is concerned (1). Since then it has been established tilat zinc deficiency does occur in man. Tile syndrome has been described in individuals from tile United States (2) as well as from Middle Eastern villages (3). Today. tile United States population consuines more highly refined foods, food product analogs, and empty calories than in the past. This change in habits should concern nutrition scientists because an inappropriate, excessive consumption of relatively non-nutritious food items such as certain snack foods, alcoholic beverages, and soft drinks may, in some individuals, contribute to tile occurrence of nutritional deficiencies when those foods replace conventional foods to an inordinate degree. The trace mineral content of’ such foods is of concern because, at present, knowledge of man’s requirenlents for trace elements is itlconlplete. This is especially true for five elements. Ilanlely, nickel (Ni), vanadium (V), Silicoll (Si),