This led to the nickname limey for British sailors. Linds discovery, however, was not widely accepted by individuals in the Royal Navys Arctic expeditions in the 19th century, where it was widely believed that scurvy could be prevented by practicing good hygiene, regular exercise, and maintaining the morale of the crew while on board, rather than by a diet of fresh food.During the late 18th and early 19th centuries, the use of deprivation studies allowed scientists to isolate and identify a number of vitamins. Lipid from fish oil was used to cure rickets in rats, and the fat-soluble nutrient was called "antirachitic A". Thus, the first "vitamin" bioactivity ever isolated, which cured rickets, was initially called "vitamin A"; however, the bioactivity of this compound is now called vitamin D. In 1881, Russian medical doctor Nikolai I. Lunin studied the effects of scurvy at the University of Tartu. He fed mice an artificial mixture of all the separate constituents of milk known at that time, namely the proteins, fats, carbohydrates, and salts. The mice that received only the individual constituents died, while the mice fed by milk itself developed normally. He made a conclusion that substances essential for life must be present in milk other than the known principal ingredients. However, his conclusions were rejected by his advisor, Gustav von Bunge.In East Asia, where polished white rice was the common staple food of the middle class, beriberi resulting from lack of vitamin B1 was endemic.
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.