Goitre an underactive thyroid, thyroid supplements are used as treatment. Sometimes a partial or complete thyroidectomy is required. Goitre is more common among women, but this includes the many types of goitre caused by autoimmune problems, and not only those caused by simple lack of iodine. Chinese physicians of the Tang Dynasty (618–907) were the first to successfully treat patients with goitre by using the iodine-rich thyroid gland of animals such as sheep and pigs—in raw, pill, or powdered form. This was outlined in Zhen Quan's (d. 643 AD) book, as well as several others. One Chinese book, "The Pharmacopoeia of
Vitamin A deficiency Organization (WHO), VAD is under control in the United States, but in developing countries, VAD is a significant concern. Globally, 65% of all children aged 6 to 59 months received two doses of vitamin A in 2013, fully protecting them against VAD (80% in the least developed countries). The common cause of blindness in developing countries is Vitamin A deficiency (VAD). The WHO estimated in 1995 that 13.8 million children to have some degree of visual loss related to VAD. Night blindness and its worsened condition, xerophthalmia, are markers of Vitamin A deficiency (VAD) and collections of keratin in the