When the article was translated into German, the translation failed to state that it was a newly discovered nutrient, a claim made in the original Japanese article, and hence his discovery failed to gain publicity. In 1912 Polish-born biochemist Casimir Funk, working in London, isolated the same complex of micronutrients and proposed the complex be named "vitamine". It was later to be known as vitamin B3 (niacin), though he described it as "anti-beri-beri-factor" (which would today be called thiamine or vitamin B1). Funk proposed the hypothesis that other diseases, such as rickets, pellagra, coeliac disease, and scurvy could also be cured by vitamins. Max Nierenstein, a friend and reader of Biochemistry at Bristol University, reportedly suggested the "vitamine" name (from "vital amine"). The name soon became synonymous with Hopkins "accessory factors", and by the time it was shown that not all vitamins are amines the word was already ubiquitous. In 1920, Jack Cecil Drummond proposed that the final "e" be dropped to deemphasize the "amine" reference, after researchers began to suspect that not all "vitamines" (in particular, vitamin A) have an amine component.In 1930, Paul Karrer elucidated the correct structure for beta-carotene, the main precursor of vitamin A, and identified other carotenoids. Karrer and Norman Haworth confirmed Albert Szent-Györgyis discovery of ascorbic acid and made significant contributions to the chemistry of flavins, which led to the identification of lactoflavin. For their investigations on carotenoids, flavins and vitamins A and B2, Karrer and Haworth jointly received the Nobel Prize in Chemistry in 1937.
Biofortified sweet potato, maize, and cassava were other crops introduced to enhance the content of beta-carotene and certain minerals.When eaten, beta-carotene is a provitamin, converted to retinol (vitamin A). The concept is that in areas of the world where vitamin A deficiency is common, growing and eating this rice would reduce the rates of vitamin A deficiency, particularly its effect on childhood vision problems. As of 2018, fortified golden crops were still in the process of government approvals, and were being assessed for taste and education about their health benefits to improve acceptance and adoption by consumers in impoverished countries. Hypervitaminosis
Some vitamins cause acute or chronic toxicity, a condition called hypervitaminosis, which occurs mainly for fat-soluble vitamins if over-consumed by excessive supplementation. Hypervitaminosis A and hypervitaminosis D are the most common examples. Vitamin D toxicity does not result from sun exposure or consuming foods rich in vitamin D, but rather from excessive intake of vitamin D supplements, possibly leading to hypercalcemia, nausea, weakness, and kidney stones.The United States, European Union and Japan, among other countries, have established "tolerable upper intake levels" for those vitamins which have documented toxicity. History
In 1747, the Scottish surgeon James Lind discovered that citrus foods helped prevent scurvy, a particularly deadly disease in which collagen is not properly formed, causing poor wound healing, bleeding of the gums, severe pain, and death. In 1753, Lind published his Treatise on the Scurvy, which recommended using lemons and limes to avoid scurvy, which was adopted by the British Royal Navy.