Scurvy observed in any organism apart from humans and had been considered an exclusively human disease. Certain birds, mammals, and fish are susceptible to scurvy, but pigeons are unaffected, since they can synthesize ascorbic acid internally. Holst and Frølich found they could cure scurvy in guinea pigs with the addition of various fresh foods and extracts. This discovery of an animal experimental model for scurvy, which was made even before the essential idea of "vitamins" in foods had been put forward, has been called the single most important piece of vitamin C research. In 1915, New Zealand troops in the Gallipoli
Vitamin B12 deficiency pregnant vegetarians and vegans, and not harmful in others. Risk of toxicity due to vitamin B is low. Vitamin B deficiency in the US and the UK is estimated to occur in about 6 percent of those under the age of 60, and 20 percent of those over the age of 60. In Latin America rates are estimated at 40 percent and they may be as high as 80 per cent in parts of Africa and Asia. Vitamin B deficiency can lead to anemia and neurological disorders. A mild deficiency may not cause any discernible symptoms, but as the deficiency