Scurvy -gulonolactone oxidase (GULO) enzyme, which is required in the last step of vitamin C synthesis. The genomes of these species contain GULO as pseudogenes, which serve as insight into the evolutionary past of the species. In babies, scurvy is sometimes referred to as Barlow's disease, named after Thomas Barlow, a British physician who described it in 1883. However, Barlow's disease or Barlow's syndrome may also refer to mitral valve prolapse, first described by John Brereton Barlow in 1966. Scurvy Scurvy is a disease resulting from a lack of vitamin C (ascorbic acid). Early symptoms include weakness, feeling tired, and sore
Vitamin A deficiency Vitamin A deficiency Vitamin A deficiency (VAD) or hypovitaminosis A is a lack of vitamin A in blood and tissues. It is common in poorer countries, but rarely is seen in more developed countries. Nyctalopia (night blindness) is one of the first signs of VAD. Xerophthalmia, keratomalacia, and complete blindness can also occur since vitamin A has a major role in phototransduction. The three forms of vitamin A include retinols, beta-carotenes, and carotenoids. Vitamin A deficiency is the leading cause of preventable childhood blindness, and is critical to achieving Millennium Development Goal 4 to reduce child mortality. About 250,000 to