Originally posted on  https://genesisfoods.co/blog/vitamin-a-function-rda-amp-utl-deficiency-amp-toxicity-and-what-we-use-in-our-products/25/9/2019.

Introduction

As mentioned in a previous post, we will be releasing articles on each micronutrient over time, detailing their role in the body, the recommended intake level given by various regions and the Upper Tolerable Limit, what symptoms may occur if you are getting too little (a deficiency) or too much (a toxicity), as well as the forms and amounts we use in our products. These posts will be released in the same order as nutrients are listed on the EU nutrition table.

As with previous posts, these will be displayed as a brief, bolded statement which gives the basic information, followed by a more complex, unbolded explanation.

Today’s post will be on the first of these nutrients – vitamin A.

Role of vitamin A

Vitamin A supports cell growth and health, immune function and vision. Cell growth and health is aided by vitamin A acting as an antioxidant to prevent damage from harmful, reactive cells. Vitamin A is involved in the production of different white blood cells, supporting the immune response. Finally, vitamin A aids vision by forming a molecule that generates electrical signals that stimulate the visual cortex in the brain.

Vitamin A is an antioxidant, which means they ‘fight’ free radicals in the body. Free radicals are highly reactive molecules that can cause damage to cells and DNA due to their reactivity. They can cause cell damage via what is known as oxidative stress. As the term “antioxidant” implies, they ‘fight’ against the oxidative free radicals by reacting with them, nullifying their ability to cause cellular damage and inhibit healthy cell division and growth. Leaving these free radicals in the body to cause oxidative damage to DNA can lead to the formation of cancers, so this is a particularly vital role of vitamin A. Oxidative stress has also been linked to other chronic diseases, like diabetes, heart disease and cognitive decline, so ensuring an adequate intake of vitamin A is very important.

Vitamin A also goes beyond just this, though, in terms of immune function. Vitamin A is a key component in the creation of B- and T-cells (bone-marrow cells and thymus cells respectively), which are very heavily involved in our immune system. Our immune response is very complex, but at a simple level it involves the actions of different types of these B- and T-cells. B-cells are the main cells involved in the production of antibodies for fighting off diseases, while T-cells are involved in inducing the death of cells that have been infected with viruses, or are dysfunctional or damaged for other reasons…

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