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Nutrition in Children

There are five basic food groups, vegetables, fruits, grains, dairy products and the protein groups. nutrition in children, malnutrition, vitamin deficiency. That’s something that’s got to be provided exogenously usually from your diet because our bodies cannot synthesize it at a sufficient rate to meet the needs of our body. There are some things that we can make but we can’t make enough of and we need to get them from our foods in order to avoid.

What are the eight major categories of nutrients? All of these are considered nutrients, so there are eight that our body needs that are really essential. You can’t have a normally functioning body without all of them. Be aware that when we are born we are mostly water. But when we are young adults we become more and more fat. And when we are elderly, you are 70% fat. Total body water is affected, of course, by our age, our sex, our body composition and the total body water decreases with age and changes in body fat. All pretty obvious. The consequences of providing adequate amounts of nutrients without adequate amounts of fluid, dehydration, excessive renal solid load and an inefficient use and waste of calories. What are our daily maintenance fluid requirements for infants and children? Again, it’s not uncommon to ask really simple things about how much water infants.

Breast milk or infant formulas provide the majority of fluid requirements. Human milk, 89% of it is water. Oxidation of ingested milk results in approximately 90% of volume available as free water so you often have pediatricians and family wanting to give their children additional water. Well, if there’s a question about their nutrition, if they are certainly borderline.

Energy derived from food. What will carbohydrates be worth in calories, fat and protein? It wouldn’t be unusual to have a little diet there and to ask you to figure out how many calories that patient has received. Or another way that you sometimes see problems presented is with a diet which is disproportionate in one type of food versus another, and you have to figure out which is the one that has the best distribution of calories.

Protein quality relates to the distribution and proportion of amino acids that the body is not capable of synthesizing the particular protein source. What we are saying here is, what is high quality biological protein? Well, as it turns out, the highest biological proteins turn out to be things like eggs - that’s the standard to which everything is compared, is egg white - milk proteins, meats, chicken, the fowls and the fish. It is very hard to get high quality protein from vegetables.

Three major categories of lipids in the western diet; triglycerides, vasolipids, sterol. Triglycerides are our main dietary fat and they are based on the length of the chains. Eight carbons is considered short chain fatty acids, medium chain fatty acids are 8-12 carbons, long chains are more than 12 carbons. Again, you don’t have to know which fats fit into those categories but it is important to perhaps know what the break is between these three. There are three predominant phospholipids that are in our diet. These are the three. And they are important for the cell function and membrane function. Remember, the main dietary sterol is cholesterol but a trick question is; cholesterol is not present foods of plant origin. It is only found in animal protein. And it has not been infrequent that that is the kind of question that’s asked about what’s the relationship of cholesterol to plants.

What are the two essential fatty acids? linoleic and linolenic acid. How, as a clinician, are you going to recognize somebody who has essential fatty acid deficiency? Well, these are the classical findings of someone who has essential fatty acid deficiency. The only way that adults differ from kids is that they won’t have growth failure. But in children these are the typical findings; the dermatitis is quite scaly, the patients have hair loss, they have diarrhea. It takes usually, if you restrict the diet in essential fatty acids, within a period of as little as ten days biochemically it’s apparent, and clinically shortly after that. Who are the patients at high risk for it? Premature infants who receive inadequate linoleic acid, children with fat malabsorption from hepatobiliary.

Essential fatty acid deficiency. Well, I gave you what you might be asked on a clinical basis. What might you find on the biochemical basis? Well, you may have low plasma level of linoleic and linolenic acid.

Let’s talk about the vitamins. Water soluble vitamins. These are the ones that are considered to be water soluble. So again it’s important to at least recognize them. The deficiency states with the water soluble vitamins; again, one of the typical things to recognize is that thiamin is associated with beriberi. And this is congestive heart failure, tachycardia, and peripheral edema. And the peripheral edema is believed to be associated with the congestive heart failure. So the main manifestation is by heart failure and its consequences. There is a so-called dry beriberi which also can be seen as a manifestation of B1 deficiency, which mainly has neurological manifestations associated with it and is more likely to be a complaint that one would see some of these things in the older children or adults. Again, it’s so uncommon. There are very few youngsters, at least in this country.

B12 deficiency; extremely unusual unless you have someone who has a congenital defect in absorption of B12. There’s a syndrome called Imerslund syndrome which is a congenital failure to be able to absorb vitamin B12 in the terminal ileum because they lack the binding sites in the terminal ileum for the B12.

Ascorbic acid deficiency, or scurvy. Again, these are the characteristics of it; poor wound healing, which is very similar to what you see in essential fatty acid deficiency. Be aware that bleeding problems, which also can be seen in essential fatty acid.

Niacin deficiency is probably the easiest; dermatitis, diarrhea and dementia. And the dermatitis is typically in areas where there has been exposure to the sun. So I used to have a picture of a child with pellagra and it’s disappeared, but it basically showed.

Folate deficiency. These patients get a macrocytic anemia. They are very much like patients with B12 deficiency. So they get big red blood cells, but different than patients with B12 deficiency syndrome, they get leukopenic, poor growth and gliacitis. Again, they have overlap with patients who have vitamin B and B2 deficiency, and also pyridoxine deficiency.

Now, biotin deficiency is one of the rarer types. Again, there is the overlap between this and the other vitamin B2, B6 deficiencies. Just be aware that they share some similar features. What about toxicity states? Can you get vitamin poisoning? Would you be able to recognize vitamin poisoning if you saw it? There are only three water soluble vitamins which cause toxicity when given in excess; niacin, vitamin B6 and vitamin C. Know that. How would you know niacin toxicity? These are its characteristics.

Vitamin B6 toxicity. These are basically all neurological manifestations that are seen with it. Again, it would be an unusual phenomenon to see but it does occur. Probably vitamin C toxicity would be the commonest vitamin toxicity we might see.

There are four fat soluble vitamins, A, D, E and K. What are the signs of deficiency? The characteristics that you see with vitamin A deficiency, clinical presentation, night blindness. And the other thing is xerophthalmia where they get problems like scaly-ness of the eyelids is one of the characteristics of it because it affects the skin and affects the cornea of the patient. So the cornea tends to become irregular. They also have a general problem with their skin as a result of it. Photophobia, conjunctivitis, so-called Bitot’s spots, keratomalacia, again because in vitamin A deficiency you have failure to regenerate the epithelium of the eye as well as the conjunctiva. They also get hyperkeratosis in the sun, on the skin. Poor growth, impaired resistance to infection. Vitamin D deficiency, the clinical presentation is most likely going to be rickets and it is very common - and I’ve seen this so repeatedly - that they will show you an x-ray and have you try to make a diagnosis of rickets.

Vitamin E deficiency. The clinical presentation here is hemolytic anemia in the premature infants, loss of neural integrity, neurological changes. These patients usually get problems, if you follow them, they have decreased reflexes if they get vitamin E deficiency. They then may have problems with sensory changes and have problems with positional sense.

Now what about toxicity states? They are more likely to ask a question about vitamin A toxicity. What are the characteristics of it? Increased CSF pressure with pseudotumor, an enlarged liver - they usually get a fatty kind of liver with vitamin A toxicity .

Vitamin D toxicity. These are the characteristics of it; hypercalcemia, anorexia, vomiting and poor growth. Again, that is a pretty unusual occurrence in the general population. Most parents don’t usually give that.

Selenium deficiency. Selenium is another important trace element. Again, when do we see selenium deficiency? It’s seen in patients with chronic diarrhea, because it, like zinc, is typically absorbed in the duodenum and jejunum. So if you have someone where the mucosa in those areas is substantially injured or you’ve had a major intestinal resection, they may have substantial losses of this trace element. The manifestations are; they can myositis, cardiomyopathy and macrocytic anemia. There is a disease that’s seen in China where they get the pure cardiomyopathy. There’s an area in mainland China where the soil lacks selenium and the infants and children that used to be born in that area would get a cardiomyopathy that would be fatal.

The only one I didn’t include is copper. Copper deficiency, as you know, can be associated with a couple of things. One, it can be associated with a microcytic anemia. Just remember that copper and iron are very closely related to each other and that copper is necessary for the reduction of ferric to ferrous iron. So you will see a microcytic anemia in patients who are copper deficient. You will also see, in copper deficiency, that the patients tend to have leukopenia.

Now we’ll talk a little about kwashiorkor and marasmus, because that is something that is very typically asked on the Board. Not that I know it’s going to be on, but it’s been on enough times that I know that you probably should be able to separate the two. Kwashiorkor results from a severe deficiency of protein, and less than adequate caloric intake. So patients with kwashiorkor more often than not will tend to look a bit fat or plump, because they are retaining a lot of fluid because of their hypoproteinemia, and often they have gotten a diet that seems to be more than adequate in fat and carbohydrate. Clinical presentation; patients with kwashiorkor usually are lethargic, they are apathetic, they are irritable, they are anorectic, they have poor growth.