Dosage Essay Examples

VITAMIN A

INTRODUCTION
Vitamin A is a fat soluble vitamin, also known by several other names, 3-Dehydroretinol, Axerophtholum, Retinol etc. fruits, vegetables, eggs, butter, whole milk are rich sources of Vitamin A. Meat and oily salt-water fishes are also high in Vitamin A. Deficiency of Vitamin A leads to poor vision, xerophthalmia (or dry eye), and other ophthalmologic manifestations. Studies show that vitamin A is useful in the treatment of dry eye or for eye infections like superior limbic keratoconjunctivitis (Heiting, 2015). Vitamin A can help in reducing complications of malaria, HIV, measles and diarrhea in children. It also helps in treating skin conditions like eczema, psoriasis, keratosis and other similar skin diseases having similar manifestations. It can also help in treatment of gastric ulcers, Crohn’s disease, diabetes and urinary tract infection.
Vitamin A which is derived from animal sources is also called Retinol. This is a pre- formed form of vitamin A which can be directly utilized by the body. The form of vitamin which is obtained from plant sources is called pro vitamin or carotenoid. They are then converted into retinol for absorption by the body.

Daily recommended dietary intake of vitamin A in adults should be 0.7mg for men and 0.6mg for women (Nhs.uk, 2015). Intake of Vitamin A is safe till 10,000 units per day are taken orally or injected in the muscles. It is unsafe and may lead to side effects or complications if taken beyond the specified doses orally. High doses of vitamin A may lead to early predisposition to osteoporosis and hence hip fractures, as proved in some scientific researches. Prolonged usage may lead to stomach ailments, depression, fever, vomiting and anorexia. High doses of vitamin A or hypervitaminosis A in pregnant women can lead to birth defects in the fetus. Pregnant women should take special care while adjusting the dosage of vitamin A intake during the first three months of conception as it is the most likely period when the fetus may acquire birth defects.
Alcohol consumption may lead to harmful effects on the liver which may arise as a result of Vitamin A intake. Infestation of hook- worms in the intestine may lead to decreased absorption of Vitamin A. In patients in whom the protein level is lesser than normal, there can be a relative hypervitaminosis A, which can be very harmful for the body (Webmd.com).
In the article by Kristina L Penniston and Sherry A Tanumihardjo they say that the sub toxicity without any clinical sign is an issue of serious concern. In developed countries people very often suffer from hypervitaminosis, however in developing countries large doses of vitamin A are required to be administered to the pregnant women and the newborn infants. The article is titled as “Acute and Chronic Effects of Toxicity of Vitamin A”, this means that it should mention the effects of toxicity, but actually it does not mention anything about the effects of toxicity of vitamin A. However, it does bring about the important issue of hypervitaminosis A in developed countries and on the contrary, deficiency of vitamin A in developing countries people. Thus I feel the article is worth reading and recommending to others (Penniston and Tanumihardjo, 2005). The article gives a detailed insight into the contrast in the vitamin A level all over the world in different countries.

References

Heiting, G. (2015). Vitamin A and Beta Carotene: Eye Benefits. All About Vision. Retrieved 11 April 2015, from http://www.allaboutvision.com/nutrition/vitamin_a.htm
Nhs.uk,. (2015). Vitamins and minerals - Vitamin A - NHS Choices. Retrieved 11 April 2015, from http://www.nhs.uk/Conditions/vitamins-minerals/Pages/Vitamin-A.aspx
Penniston, K., & Tanumihardjo, S. (2005). The acute and chronic toxic effects of vitamin A1,2,3,4. The American Journal Of Clinical Nutrition, 83(2), 191-201.
Webmd.com,. (2015). vitamin a: Uses, Side Effects, Interactions and Warnings - WebMD. Retrieved 11 April 2015, from http://www.webmd.com/vitamins-supplements/ingredientmono-964-vitamin%20a.aspx?activeingredientid=964&activeingredientname=vitamin%20a