Vitamin A

Efficacy of Vitamin A as an Alternative Medicine According to GRADE* Ranking: 

Conjunctivitis [1, 2, 3, 4, 5, 6, 7, 8]:

Recommendation: Strongly in favor (Vitamin A may help to prevent conjunctivitis due to its role in the body's immune function)

Grade of Evidence: High level of evidence

Genital Herpes Simplex [9, 10]:

Recommendation: No recommendation (There is insufficient evidence to support claims that vitamin A supplements are able to help treat genital herpes.)

Grade of Evidence: Low level of evidence

Lower Respiratory Tract Infection [1, 2, 3, 4, 5, 6, 7, 8]:

Recommendation: Strongly in favor (Vitamin A may help to prevent respiratory tract infections due to its role in the body's immune function)

Grade of Evidence: High level of evidence

Lower Urinary Tract Infection [1, 2, 3, 4, 5, 6, 7, 8]:

Recommendation: Strongly in favor (Vitamin A may help to prevent urinary tract infections due to its role in the body's immune function)

Grade of Evidence: High level of evidence

Respiratory Tract Infection [1, 2, 3, 4, 5, 6, 7, 8]:

Recommendation: Strongly in favor (Vitamin A may help to prevent respiratory tract infections due to its role in the body's immune function)

Grade of Evidence: High level of evidence

Upper Urinary Tract Infection [1, 2, 3, 4, 5, 6, 7, 8]:

Recommendation: Strongly in favor (Vitamin A may help to prevent urinary tract infections due to its role in the body's immune function)

Grade of Evidence: High level of evidence

Anorexia Nervosa [1, 2, 3, 4, 5, 6, 7, 8]:

Recommendation: Strongly in favor (Vitamin A may help to prevent/treat anorexia due to it's role in improving poor appetite)

Grade of Evidence: High level of evidence

Bacterial Urinary Tract Infection [1, 2, 3, 4, 5, 6, 7, 8]:

Recommendation: Strongly in favor (Vitamin A may help to prevent urinary tract infections due to its role in the body's immune function)

Grade of Evidence: High level of evidence

Cystic Fibrosis [11]:

Recommendation: No recommendation (There is insufficient evidence to support claims that vitamin A supplements are able to help treat cystic fibrosis. More studies needed)

Grade of Evidence: Very low level of evidence

Diarrhoea [1, 2, 3, 4, 5, 6, 7, 8]:

Recommendation: Strongly in favor (Vitamin A may help to prevent diarrhoea due to its role in the body's immune function)

Grade of Evidence: High level of evidence

Fungal Urinary Tract Infections [1, 2, 3, 4, 5, 6, 7, 8]:

Recommendation: Strongly in favor (Vitamin A may help to prevent urinary tract infections due to its role in the body's immune function)

Grade of Evidence: High level of evidence

Herpes Simplex Virus Infections [9, 10]:

Recommendation: No recommendation (There is insufficient evidence to support claims that vitamin A supplements are able to help treat genital herpes)

Grade of Evidence: Low level of evidence

Travellers Diarrhea [1, 2, 3, 4, 5, 6, 7, 8]:

Recommendation: Strongly in favor (Vitamin A may help to prevent diarrhoea due to its role in the body's immune function)

Grade of Evidence: High level of evidence

Urinary Tract Infection (Cystitis) [1, 2, 3, 4, 5, 6, 7, 8]:

Recommendation: Strongly in favor (Vitamin A may help to prevent urinary tract infections due to its role in the body's immune function)

Grade of Evidence: High level of evidence

Lung Cancer [1, 2, 3, 4, 5, 6, 7, 8]:

Recommendation: Weakly against (Clinical trials have shown that not only do vitamin A supplements not lower the risk of lung cancer in smokers, it actually increases the risk of death from lung cancer and heart disease.)

Grade of Evidence: High level of evidence

Acute Promyleocytic Leukemia [1, 2, 3, 4, 5, 6, 7, 8]:

Recommendation: Weakly in favor (Promyelocytic Leukemia often responds positively to a combination of Vitamin A and chemo therapy. This must be done under the supervision of an oncologist. Taking non prescription supplements or increasing dietery intake without a doctors supervision will not necessarily improve outlook of leukemia.)

Grade of Evidence: Moderate level of evidence

* www.gradeworkinggroup.org 

References: 

1. htt p://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-vitamina.html

2. http://www.nlm.nih.gov/medlineplus/vitamina.html

3. http://ods.od.nih.gov/factsheets/vitamina.asp

4. http://www.who.int/nutrition/topics/vad/en/

5. Latham, Michael E. (1997). Human Nutrition in the Developing World (Fao Food and Nutrition Paper). Food & Agriculture Organization of the United. ISBN 92-5-103818-X.

6. Sommer, Alfred (1995). Vitamin a Deficiency and Its Consequences: A Field Guide to Detection and Control. Geneva: World Health Organization. ISBN 92-4-154478-3.

7. http://www.unicef.org/worldfitforchildren/files/A-RES-S27-2E.pdf

8. Ades T, Alteri R, Gansler T, Yeargin P, "Complete Guide to Complimentary & Alternative Cancer Therapies", American Cancer Society, Atlanta USA, 2009