Vitamin A
Toxicity of Vitamin A
Toxic effects of excessive intake of vitamin A
Hypervitaminosis A refers to an abnormal deposition in the body in large amounts of vitamin A (retinol).
Normally this is given by the excessive intake of vitamin supplements.
There are several side effects among which are:
* Birth defects: is when the supplement that has high doses of retinol ingested for a while, several days or weeks and especially during the first trimester of pregnancy.
* Abnormalities in the liver.
* Reduced bone mineral density.
* Central nervous system disorders.
Signs and symptoms of toxicity or hypervitaminosis (excess of vitamin A) can be:
Anorexia, weight loss, vomiting and nausea, blurred vision, irritability, hepatomegaly, alopecia, headaches, insomnia, weakness, poor muscle strength amenorrhea (cessation of menstrual period), hydrocephalus and cranial hypertension in children. Read the rest of this entry »
The Main Sources of Vitamin A
The main sources of vitamin A are:
In the animal kingdom: dairy products, egg yolks and fish liver oil.
In plants: All plants yellow to red, or dark greens, carrots, sweet potatoes, pumpkins, squash, peppers, spinach, radicchio, lettuce, broccoli, Brussels sprouts, tomatoes, asparagus
In fruit: Damascus, peach, melon, papaya, mango, papaya
Consequences of lack or deficiency of vitamin A
Lack of vitamin A enters brings several consequences which are:
* Eye disorders: Twilight may cause blindness, ie visual acuity decreases at night, extreme sensitivity to light as well as dryness, opacity of the cornea ulcers, called xerophthalmia, which can lead to blindness
* Low immunity (low defenses) increases susceptibility to bacterial, parasitic or viral infections and vitamin A contributes to the maintenance of mucosal integrity. Lacking she disappears barrier against infections. Immune system cells are also affected which may lead to an increase in pre-cancerous cells of epithelial tissues of the mouth, throat and lungs. Read the rest of this entry »
Vitamin A Benefit for The Body
Brief definition
Belongs to a group of fat soluble vitamins (soluble in fat) is essential for the body.
This vitamin is present in foods of animal origin as a pre-formed vitamin A and retinol is called while the plant appears as provitamin A, also known as carotenoids (or carotenoids) among which stands out the beta carotene.
Beta carotene are natural pigments that are found in fruits and vegetables red, orange and yellow, or in dark green vegetables. Beta-carotene is a chemical form required by the body for the formation of vitamin-A.
Approximately 80 to 90% of the esters of retinol absorbed while beta carotene do between 40 to 60%. The majority of vitamin A, almost 90% is stored in the liver, the remainder being deposited in the lungs, kidneys and body fat.
Functions of Vitamin A and retinol in the body:
* Skeletal system: it is necessary for growth and bone development.
* Cell development: essential for growth, maintenance and repair of mucosal cells, epithelium, skin, vision, nails, hair and tooth enamel. Read the rest of this entry »