Vitamin A (Retinol, Retinoic Acid, Retinal)

00:00 In this lecture I'll cover everything that you need to know for your exams about fat soluble vitamins.

00:09 Go ahead pull up the visual.

00:12 How do we remember, what the fat soluble vitamins are? Well I hope you remembering the big fat naked lady on the beach.

00:21 Because we have a little "n" then we start with "A." So A is retinol or retinoic acid or retinal.

00:31 In the fat soluble vitamins, again we generally go with the latter.

00:36 But I'm giving you the names so you have some associations.

00:39 But depending on it's form, it could have a different name so it can get a little confusing.

00:44 So I really recommend keeping track of the latter name for these vitamins.

00:49 Retinol is involved in the retina and rhodopsin.

00:58 So it's involved in the pigment of rhodopsin.

00:59 And thus, associated with night vision.

01:03 We also know that vitamin A is involved in skin issues.

01:07 Treatment with retina or retinoic acid.

01:12 It is common for acne and the renewal of the skin.

01:16 And it's also involved in cell differentiation.

01:20 So in cell differentiation, I have an example here where vitamin A can be used as a treatment for acute myeloid leukemia.

01:29 What happens in that case is, we end up with a number of progenitor cells or over abundance of progenitor cells that are not maturing.

01:39 And this has to do with a retinol receptor.

01:42 And the retinol receptor is defective.

01:45 So there is some thought that treatment with additional vitamin A can increase the production of these erythrocytes and mast cells and so on and so forth.

01:55 Maturation of the red blood cell, I mean, white blood cell line.

01:59 So next we'll look at vitamin A deficiency.

02:03 Clearly you can guess what those deficiencies result in based on the role of vitamin A.

02:10 So Nyctalopia or poor night vision, poor skin health and cell differentiation issues in bone.

02:20 And skin and any other cell well there is differentiation.

02:24 Particularly in the blood also.

02:27 So things to keep in mind about vitamin A.

02:31 And with that we shall move on to the toxicity of vitamin A.

02:36 There are fairly non specific symptoms for deficiency.

02:43 So nausea, irritability, headaches, some visual problems, maybe skin or hair issues.

02:48 And it's certainly something to consider with the toxicity, is it is teratogenic to fetuses.

02:57 So we certainly don't want to be using any of the retinol promoting drugs.

03:07 Like you would use accutane for acne or something during pregnancies.

03:12 So that's one thing to consider with toxicity.

03:15 Again we are in the fat soluble vitamins.

03:17 So these can accumulate toxicity much more easily than deficiency.