Mechanism of Action: Vitamin A (all-trans retinol) is converted in the retina to the 11-cis-isomer of retinaldehyde or 11-cis-retinal. 11-cis-retinal functions in the retina in the transduction of light into the neural signals necessary for vision. 11-cis-retinal, while attached to opsin in rhodopsin is isomerized to all-trans-retinal by light. This is the event that triggers the nerve impulse to the brain which allows for the perception of light
Pharmacology & Brands Available:
Available Brands of Vitamin A in Kenya
Vitamin A Capsules USP 200000 IU , Galaxy Pharmaceutical Limited
Vitamin A, Marketed by Ray Pharmaceuticals
Retinol® 200,000 IU , Lambo Laboratories S.A / N.V
Retinol® 50000 I.U Capsules ,Lambo Laboratories S.A / N.V
Vitamin A, Modern Pharmaceuticals Ltd. ( Tabs 200,000 IU)
Reveve®, Yash Pharma Laboratories Pvt. Ltd
Gel Soft Gelatin®, Renata Limited
Dietary vitamin A is derived from a variety of carotenoids found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products.
Vitamin A plays a role in a variety of functions throughout the body, such as:
- Gene transcription
- Immune function
- Embryonic development and reproduction
- Bone metabolism
- Skin and cellular health
- Mucous membrane
- Vitamin A deficiency- Vitamin A deficiency can occur as either a primary or a secondary deficiency. A primary vitamin A deficiency occurs among children and adults who do not consume an adequate intake of provitamin A carotenoids from fruits and vegetables or preformed vitamin A from animal and dairy products. Secondary vitamin A deficiency is associated with chronic malabsorption of lipids, impaired bile production and release, and chronic exposure to oxidants, such as cigarette smoke, and chronic alcoholism
- Vitamin A supplementation-
Excessive vitamin A consumption can lead to nausea, irritability, anorexia (reduced appetite), vomiting, blurry vision, headaches, hair loss, muscle and abdominal pain and weakness, drowsiness, and altered mental status
Some products that may interact with this vitamin A include: acitretin, alitretinoin, bexarotene, cholestyramine, isotretinoin, tretinoin.
This document does not contain all possible drug interactions. Keep a list of all the products you use. Share this list with your doctor and pharmacist to lessen your risk for serious medication problems.