Search results
Results from the WOW.Com Content Network
Vitamin A deficiency (VAD) or hypovitaminosis A is a lack of vitamin A in blood and tissues. [1] It is common in poorer countries, especially among children and women of reproductive age, but is rarely seen in more developed countries. [1] Vitamin A plays a major role in phototransduction, so this deficiency impairs vision, often presenting ...
Vitamin deficiency is the condition of a long-term lack of a vitamin. When caused by not enough vitamin intake it is classified as a primary deficiency, whereas when due to an underlying disorder such as malabsorption it is called a secondary deficiency. An underlying disorder can have 2 main causes:
It may be caused by vitamin A deficiency, [1] which is sometimes used to describe that condition, although there may be other causes. Xerophthalmia caused by a severe vitamin A deficiency is described by pathologic dryness of the conjunctiva and cornea. The conjunctiva becomes dry, thick and wrinkled. The first symptom is poor vision at night.
Scurvy is a deficiency disease (state of malnutrition) resulting from a lack of vitamin C (ascorbic acid). [1] Early symptoms of deficiency include weakness, fatigue, and sore arms and legs. [ 1 ] [ 2 ] Without treatment, decreased red blood cells , gum disease, changes to hair, and bleeding from the skin may occur.
Vitamin A deficiency has been linked to compromised resistance to infectious diseases. [33] [34] In countries where early childhood vitamin A deficiency is common, vitamin A supplementation public health programs initiated in the 1980s were shown to reduce the incidence of diarrhea and measles, and all-cause mortality.
Vitamin B12 deficiency symptoms . Vitamin B12 deficiency has a few hallmark symptoms, according to doctors: Lack of energy. Mental fatigue. Nausea, vomiting, or diarrhea. Lack of appetite. Weight loss
Undernutrition can cause vitamin-deficiency-related diseases like scurvy and rickets. As undernutrition worsens, those affected have less energy and experience impairment in brain functions. This can make it difficult (or impossible) for them to perform the tasks needed to acquire food, earn an income, or gain an education. [citation needed]
The Mayo Clinic's website says when there is a reaction: "The main consequence of vitamin D toxicity is a buildup of calcium in blood (hypercalcemia), which can cause poor appetite, nausea and ...