Vitamin B1 and B2

00:00 Hello, this is the first in a series of two lectures on water soluble vitamins.

00:07 We're going to explore the majority of the B vitamins in this lecture.

00:11 We'll begin by looking at thiamin.

00:15 Thiamin is B1.

00:16 Why don't we just work our way straight through the numbers.

00:19 In this lecture I'm going to highlight the parts that you need to know about each of these vitamins.

00:26 Yes, there are many more potential functions.

00:29 And things that you could know.

00:32 But these are the highlights that you need for your exams.

00:35 First of all vitamin B1, thiamin, is the most -- is a very important cofactor in many metabolic processes.

00:42 You can see here for example, pryuvate dehydrogenase and alpha-ketogluterate, really depend on the B1 vitamin as a cofactor.

00:53 This is found in many foods.

00:56 And we fortify many foods with it also.

01:00 And so we rarely see a deficiency in the United States.

01:06 The one exception though is in the condition of alcoholism.

01:10 Because often in alcoholism the majority of calories are coming from alcohol unless there is some deficiency in other nutrients.

01:19 And so there are three conditions associated with B1 deficiency that you should be very clear about.

01:28 Those three conditions are Dry Beri-Beri, Wet Beri-Beri and Wernicke Korsakoff.

01:34 In dry beri-beri we have predominantly effects of the nervous system.

01:39 We'll see things like symmetrical muscle wasting.

01:43 So both sides are getting very weak.

01:45 As well as peripheral neuropathy, confusions.

01:50 Sometimes difficulty speaking and involuntary eye movements.

01:55 So nystagmus would be constant in this case.

01:59 So looking at someone's whose eyes are constantly shaking back and forth.

02:04 Nystagmus would be a good indication of dry beri-beri and perhaps vitamin 1 deficiency.

02:11 Wet beri-beri on the other hand has much more to do with cardiac systems.

02:17 Individuals may have signs of both dry and wet beri-beri.

02:22 And in the case of wet beri-beri we have shortness of breath, rapid heart rate.

02:28 More things associated with the circulatory system like edema in the lower legs.

02:34 And this can even lead to cardiac failure.

02:37 On top of this we could stack wernicke korsakoff.

02:41 So these two have neurological and cardiac symptoms respectively.

02:48 Wernicke korsakoff will start seeing both of those also and more extensive neurological symptoms.

02:56 Wernicke korsakoff is described as a set of symptoms that lead to confusion.

03:04 Again we'll have not just the involuntary eye movements but perhaps even constant.

03:09 Nystagmus.

03:10 Aphasia where an individual is sort of moving in and out of understanding things.

03:16 Ataxia as well as memory loss.

03:21 And confabulation is one of the biggest symptoms.

03:26 So individuals with wernicke korsakoff have mamillary body damage in the brain areas.

03:32 And they will tend to confabulate meaning make up stories.

03:38 That are sounding really extreme explanations for what's actually going on.

03:44 So there's a certain sort of detachment from reality.

03:49 It's a pretty clear syndrome.

03:51 When you see someone presenting with this type of confusion and very extreme exaggerated types of stories.

03:59 There's a possibility that it could result from a B1 deficiency and alcoholism.

04:05 Moving on to vitamin B2, riboflavin.

04:09 Riboflavin is also involved in many metabolic pathways.

04:15 For example, that's involved in the synthesis of FAD.

04:19 Here we call FAD is an electron carrier and thus is involved in energetic relationship.

04:26 So you'll notice a lot of these B vitamins are involved in metabolic processes.

04:32 As well as production of red blood cells.

04:34 So this is a fairly common B.

04:37 Deficiency in riboflavin is very rare in the US.

04:41 I have for eating fresh foods, with vegetables and good diet than it shouldn't really be an issue.

04:49 Plus, we supplement many of our packaged foods with riboflavin.

04:54 Causes of riboflavin deficiency could be malnutrition in developing countries, alcoholism, vegan diets, and pregnancy. Signs and symptoms are cheilitis, glossitis, and stomatitis; pharyngitis; normocytic normochromic anemia; red-eye and photophobia; and seborrheic dermatitis on the scrotum, vulva, philtrum of the lip, or the nasolabial folds.