Introduction
Vitamin A has for a long time been considered to play a crucial role in the normal biological and metabolic functions of the human body. It can be introduced into the body in form of supplements such as cod liver oil which contains the “cis” form of vitamin A, vegetable sources such as carrots, squashes, and most dark green leafy vegetables and animal sources, such as eggs, meat, fish and milk. Vitamin A is fat-soluble and is readily absorbed in the body, though the supplement form is more soluble and easily degenerated (USDA, 2008). Biological estimation of vitamin A is the method most frequently used in the curative analysis of vitamin A assay and live test subjects are commonly used. In 2006-2009, curative analyses of vitamin A assay were carried out by several laboratories in a series of tests to discern the major functions of vitamin A.
Procedure
The test subjects which were usually rats or primates were deprived of Vitamin A and allowed to exhaust all the vitamin A stored in the fatty tissues of their body. The deficiency of the vitamin was then ascertained by the stunted growth of the younger test subjects, though the rest of the dietary supplements were included in their daily diets (Nelson, 2008). A specific dosage of vitamin A was then administered daily for seven weeks and the findings were documented. It was determined that the test subjects recorded an increase in body mass, body weight, and an accelerated rate of growth after being administered vitamin A for four weeks (Master john, 2006). There was however irregularity in the findings because there were different rates of growth and the increase in body mass and weight. Researchers in an attempt to control such irregularities deemed it necessary in 2006 to adhere to strictly using younger test subjects with similar genetic markups to obtain more accurate results. In 2007, test subjects were crossed to produce a high breed litter which was the main focus of the experiment for by comparing test results on animals from a similar litter could the results of the curative analysis in vitamin A assay be more precise. Stunted growth was also not highly regarded as an indication of Vitamin deficiency; rather scientists determined the depletion of vitamins through the manifestation of avitaminosis-A or vitamin A deficient conditions like xerophthalmia (Nelson, 2008).
The incongruity of the assay
A critical analysis of the curative assay of vitamin A reveals fundamental inconsistencies that are more likely than not, capable of totally altering the results and conclusive findings. In 2007, it was determined that the analysis of vitamin A was entirely based on growth, mass, and weight, but ignored the holistic function of the vitamin on the organism (Nelson, 2008).
Stunted growth was being considered the standard for determining the deficient conditions of vitamin A and the commencement of growth in the presence of vitamin A. Other important microbiological and metabolical conditions were not taken into account and consequently, this analysis became flawed. In 2008, scientists started to consider more adverse conditions like diseases and organ failure as linked to a deficiency of vitamin A (Takita, et al, 2006). These conditions had previously been ignored and considering they appeared differently on different test subjects, the introduction of vitamin A on previous subjects also gave different results. The current consideration of ailment onset is working positively in helping scientists better identify the adverse effects of vitamin A depletion.
Medical application of vitamin A assay
By thoroughly scrutinizing the effects of vitamin A deficiency, scientists have been able to come up with substantial theories of the function of vitamin A in the body. Apart from maintaining good eyesight, vitamin A has also been discovered to perform curative functions among individuals with certain diseases. Scientists and researchers had come up with concepts to support the key roles of vitamin A through the study of test subjects and these functions were integrated into the medical and pharmaceutical fields (McGuire & Kathy, 2007).
Immune system booster
A recent study has revealed that vitamin a plays an important role in constantly upgrading the immune system by increasing the number of white blood cells. Studies have shown that vitamin A is absorbed into the lymphatic system through the intestines since it is fat-soluble (McGuire & Kathy, 2007). Once in the lymphatic system, it acts on the white cell deposits by inducing cell regeneration and multiplication consequently increasing the number of white blood cells in the body (Nelson, 2008). Supplements containing vitamin A were therefore used together with other medication in treatment or slowing the progression of diseases such as HIV and AIDS, tuberculosis, and asthma. For example, a recent study by WHO carried out in Burkina Faso revealed that young children were more likely to respond faster to malaria medication if they had previously consumed supplements of vitamin A.
Lung cancer
Vitamin A has also been found to drastically reduce the number of cells that cause lung cancer in former smokers. A recent study has shown that former smokers are still at risk of contracting lung cancer since mutant cells damaged by the tar in cigarette smoke could still be able to grow in the lungs. Vitamin A is suspected to act on these mutant cells by reducing their growth and consequently reducing the chances of getting the disease. A report by Medical News Today on research carried out by the University of Texas on 200 former smokers revealed that the retinoic acid form of vitamin A was highly potent in negating the effects of tobacco on lung cells (McGuire & Kathy, 2007)
Autism
According to (Schulz et al, 2007), vitamin A has also been recently discovered to produce positive effects on children suffering from autism. Carotenoids administered to children suffering from autism with a recommended daily dosage of 6000 IU showed that the children improved in terms of concentration, memory, communication, and social skills.
Infertility
A study was done in the year 2007 on rats that were deprived of any intake of vitamin A for a prolonged period. The rats exhibited signs of low libido and eventually infertility. However, the re-introduction of vitamin A into their diet enabled the rats to gradually gain fertility. (Takita et al, 2006). Humans are also likely to suffer from infertility through the deficiency of vitamin A in their diet. The primary deficiency of vitamin A is the lack of sufficient quantities of vitamin A in the body, but this deficiency can easily be corrected by the introduction of nutritional values and a balanced diet. Secondary deficiency occurs when an individual’s body fails to absorb vitamin A even though it is consumed regularly (Schulz et al, 2007). This could either be due to zinc deficiency, low fats in the body, disease, or a malfunctioning organ in the body like the liver or the pancreases (Masterjohn, 2006). Here, medical attention is necessary and vitamin A can be taken in form of supplements. According to the world health organization (WHO), a global organization that studies and provides adequate nutrition, Vitamin A deficiency is a major cause of infertility among adults in developing countries. Research has gone into finding a permanent cure for infertility through the use of vitamin A.
Child blindness
Vitamin A deficiency mostly affects young children and there are currently more than three million children globally suffering from vitamin A deficiency blindness. Children in developing nations especially those in the Asian and African continents are at a high exposure to chronic immune malfunction and total blindness due to the lack of this vitamin (USDA, 2008). Supplements and distribution models are still being put together and according to Takita et al (2006), plans are underway to use vitamin A to produce drugs to fight the persistent blindness in these third world countries.
Conclusion
Vitamin A has gained increased medical interest especially for its ability to strengthen the immune system which is one of the major problems the medical field endures to control. This has led to the discovery of its antibiotic qualities such as being antibacterial. The cell regeneration qualities of vitamin A have also led scientists to believe it has anti-aging properties and several dermatological creams from 2006 have been based on vitamin A. There is still a lot of research going into this vital resource but scientists are expressing optimism that a lot more medical value will be derived from vitamin A.
References
Masterjohn, C (2006).
Vitamin D toxicity redefined: vitamin K and the molecular mechanism. Web.
McGuire, M and Kathy A (2007). Nutritional sciences: from fundamentals to food. Belmont: Thomson/Wadsworth.
Nelson, A. (2008). “Neutrophil gelatinase-associated lipocalin mediates 13-cis retinoic acid-induced apoptosis of human sebaceous gland cells”. Journal of Clinical Investigation 118 (4)
Schulz C, Engel U, Kreienberg R and Biesalski H (2007). Vitamin A and beta-carotene supply of women with Gemini or short birth intervals: a pilot study. Mongolia: Flixd publishers.
Takita Y, Ichimiya M, Hamamoto Y, and Muto M (2006). A case of carotenemia associated with ingestion of nutrient supplements. London: beeline publishers.
United States Department of Agriculture USDA (2008). Composition of Foods Raw, Processed, Prepared. Chicago: Kniff.