Health hazards caused by vitamin A and beta carotene (provitamin A)
The fat Vitamin A and its precursor, the
pro-beta carotene (which the organism is converted to vitamin A) meet as nutrients important functions in the body. They are important for growth, reproduction and for the skin necessary for the Sehprozess, and important for the immune system and regeneration of the mucous membranes.
As a possible deficiency symptoms are worsening eye functions and eye damage with the risk of blindness, an increased Infektrisiko and respiratory complaints.
To compensate for the lack to act contrary to appearances, these and other vitamins in many food supplements. But there is in today's Ernähungsgewohnheiten real risk of vitamin deficiency?
In the food industry is beta carotene as a yellow-red dye many foods such as margarine, orange soft drinks, juices, added. Vitamin A is particularly fat and oily foods such as meat - and sausages, as anti-oxidant attached. The use as a food additive and natural resources in some foods (liver, carrots, peppers, vegetable oils, margarine, etc.) can doubt that the fear of a vitamin deficiency in a balanced diet still justified today. Rather, the injection of some high-dose vitamin preparations and food supplements the risk of overdoses cause.
The authors, some examples on the health hazards caused by vitamin overdoses can arise. For the vitamin A and beta carotene, the following symptoms, which after a regular intake of high doses were observed:
-- Abnormalities in children and growth by reducing the increased vitamin intake during pregnancy. It also can lead to high revenue of vitamin A toxic effect on the child.
-- Increasing the risk of osteoporosis disease. Vitamin A speeds up the bone degradation, and inhibits the activity of vitamin D (calcium deposits in the bones).
-- Increase blood fat levels.
-- Increase the risk of lung cancer in smokers. One Finnish study found, at the thirty thousand smokers participated, sick people, the daily 20 mg beta-carotene supplements were given to 18% more frequently from lung cancer. The mortality rate rose by 8%. An American study of smokers and around 18,000 people, the burden of asbestos were led to similar results. This increased the lung cancer cases in the group, the daily 30 mg beta-carotene and vitamin A were given to 28%. The number of deaths from lung cancer rose by 46%.
-- Asthma. A regular intake of vitamin A in higher doses should be according to a study by the College of Health Sciences (Iowa) to severe asthmatic attacks.
-- Vomiting, loss of appetite, Hautabschuppungen.
-- Liver enlargement, liver damage.
-- Swelling of lymph glands and joints.
-- Drying out the skin, hair loss.
It can not be excluded that some of the most sought-after and described positive effects of these vitamins are unfounded. As pharmacologists Association of the USA (USPC) said, the benefits of vitamin A against the following complaints not proven:
-- Eye problems, dry and oily skin, kidney stones, the thyroid function, anemia (anemia), sunburn, lung diseases, deafness, osteoarthritis (arthritis bone participation), inflammatory bowel disease, signs of wear of the nervous system.
-- The benefits of prevention or treatment of cancer has also yet to be proven.
More short essays on "vitamin shock." Droemersche Verlagsanstalt Th Knaur Nachf, Munich, 2002; "bitter pills". Verla