Water soluble vitamins

What are the roles of gastric acid (HCl) and Intrinsic Factor (IF) in B12 absorption?

Role of gastric acid (HCl) and intrinsic factor (IF) in B12 absorption? Both release B12 from the proteins to which it is attached in foods and then in the small intestine it binds with IF, receptors at the end of the small intestine only recognize B12 when it is bound to IF and then it can be absorbed into the bloodstream

Substrate

A substance on which an enzyme acts

enzyme

A substance produced by a living organism that acts as a catalyst to bring about a specific biochemical reaction

Coenzyme

A vitamin PLUS an added molecular structure; they assist in the catalytic actions of enzymes

Why is beriberi a potential problem in populations that consume most of their kcals from "polished" rice?

The bran and germ contain Thiamin and they are removed during processing of polished (white) rice

Define a megadose of vitamin C? What is the bottom line on the effect of high doses of vitamin C on the common cold and cancer? List the side effects and negative consequences of chronically consuming high amounts of vitamin C as a daily supplement?

-Megadose of vitamin C is consuming above 2000mg a day -High doses of vitamin C show NO evidence to cure common cold or cancer -Side effects: increased risk of kidney stones, iron toxicity, erode tooth enamel, diarrhea

How much orange juice must you drink to get your RDA for vitamin C? (Look up the vitamin C content of orange juice in your diet analysis software.)

1 cup of orange juice has 84 mg vitamin C -Vitamin C RDA for those 19 and older: Men- 90 mg & Women- 75 mg It is very easy to get a lot of vitamin C.

Vitamin

A category of nutrients required in very small amounts but essential to life

4. Why are vegan vegetarians at risk for low B12 nutritional status?

Because the main source of B12 is in animal foods and vegans don't consume animal byproducts

7. Explain how in the case of alcohol abuse, an individual can rapidly develop folate deficiency. ( Hint: enterohepatic circulation).

Alcohol abuse causes less absorption of Folate into the intestines

Vitamin B6 facilitates the release of energy like other B vitamins, but from protein rather than carbohydrates and fats. Explain.

All three forms of vitamin B6 can be converted into coenzyme PLP which is active in amino acid metabolism because it can transfer amino groups from an amino acid to a keto acid Adds or removes amino groups; converts tryptophan to niacin or serotonin; synthesis of heme, nucleic acids and lecithin

What is atrophic gastritis?

Atrophic gastritis? Chronic inflammation of the stomach accompanied by diminished size and functioning of the mucous membrane and glands; characterized by inadequate HCl and IF which are 2 substances needed for B12 absorption

The water-soluble vitamins include

B&C VITAMINS B1 - thiamin B2 - riboflavin B3 - niacin B6 - pyridoxine B12 - cobalamin C - Ascorbic acid Folate, Biotin, Pantothenic acid

If someone consumes an excessive amount of the water-soluble vitamins how are they excreted from the body? Which water-soluble vitamins have UL's defined for them? Why don't the others have ULs set for them?

How will they be excreted? Kidney removes what the body can't use through the urine Which water-soluble vitamins have ULs? Vitamin C, Folate, Niacin, and Vitamin B6

Product

The compounds that are formed once a reaction goes to completion

water soluble vitamins

Carried in blood Excreted in urine Needed in frequent small doses Unlikely to reach toxic levels in body BUT: Niacin, vitamin B-6, folate, choline, and Vitamin C all have UL. Watery parts of body

Vitamins B12 chemical name and colbalts role

Chemical name? Cobalamin Cobalt's role? Contains biochemically rare element cobalt sitting in the center of planar tetrapyrrole ring called a Corrin ring

Describe in a brief sentence the roles of niacin (NADH) and riboflavin (FADH2) in ATP production.

In energy metabolism, FAD and NAD pick up hydrogen with their electrons from the TCA cycle and deliver them to the electron transport chain to produce ATP

Where was beri beri first observed?

First observed? Indonesia populations consuming polished rice

5. Why does it take years to develop B12 deficiency and only weeks or months to produce folate deficiency?

Folate is water-soluble and B12 is fat-soluble

2. Explain the statement: Vitamin B12 deficiency causes a folate deficiency. What distinguishes pernicious anemia from megaloblastic anemia (i.e. folate deficiency)? Explain the roles of folate and B12 in blood health. Now describe vitamin B12's second role in the body.

How does Vitamin B12 deficiency cause a folate deficiency? Vitamin B12 activates Folate by donating cobalt so if you are deficient in B12 then you will be deficient in Folate because it won't be activated (interdependent relationship) Pernicious anemia vs. Megaloblastic anemia? Pernicious anemia is a B12 deficiency; Folate deficiency leads to a decrease in cell division better known as Megaloblastic anemia

A person suffering from scurvy has pinpoint hemorrhaging in the skin and at points of the body where there is mechanical stress, like on the gums and joints. Why? Discuss the biological role of ascorbic acid and iron to explain this observation.

Interferes with collagen synthesis (collagen keeps cartilage healthy and strong) -Ascorbic acid/iron- vitamin C helpful in iron absorption, helps iron serve in collagen synthesis -If you aren't getting this, collagen will be weak

3. Explain the issue that prompted the Food and Drug Administration (FDA) in 1998 to approve the enrichment of flour (and other cereal products) with folate? What is neural tube defect? Why must women during their childbearing years (even before they are pregnant) be aware of their folate intake? Since fortifying the food supply in the US, has the incidence of neural tube defect been reduced to zero? List foods rich in folate.

Issue that prompted FDA to approve enrichment of flour with Folate? Half of pregnancies each year are unplanned and neural tube defects occur early in development before most women know they are pregnant Neural tube defect? Malformation of the brain, spinal cord, or both during embryonic development and often results in lifelong disability or death Women during childbearing years and Folate intake? Neural tube defects are caused by inadequate Folate intake in early weeks of pregnancy Foods rich in Folate? Vegetables, legumes, fortified grains, and oranges

What methods described in the text and class should be utilized to preserve vitamin content of foods when cooking?

Microwaving denatures B12 Refrigerating most fruits and vegetables slows denaturation Store cut up pieces of fruits and vegetables in air-tight containers while refrigerating Steam vegetables in small amounts of water Add vegetables to water once it's boiling Avoid high temperature cooking for long time periods

Common characteristics of all vitamins

Molecules of vitamins are individual units Methods of food prep can degrade some vitamins Some vitamins have more than one chemical structure with differing biological potency or different functions

What is the significance of tryptophan in the diet in terms of niacin nutrition? If you ate a nice lunch of steak and eggs, which provided 300 mg of tryptophan, how many milligrams of niacin equivalents did this meal provide?

Significance in the diet in terms of niacin nutrition? Niacin can be obtained directly from foods and can be synthesized in human cells from the amino acid tryptophan Equivalents? 60 mg of tryptophan= 1 mg niacin produced

Pellagra was in epidemic proportions in this country around 1910-1930. What are the symptoms of this disease? What were the dietary conditions, which precipitated this disease? What was the significance of a low protein diet? How did our public health

Symptoms? Diarrhea, Dermatitis, Dementia, Death Dietary conditions which precipitated this disease? Consumption of mainly corn products Significance of a low protein diet? People of low SES groups consumed most of their energy from corn products which are low in protein How did public health officials resolve this? In 1938 the US mandated fortification of processed grains such as flour and rice

Explain the roles of folate and B12 in blood health. Now describe vitamin B12's second role in the body.

They facilitate the formation of red blood cells Folate is necessary for the production and maintenance of new cells and to make DNA and RNA A deficiency in Folate might be masked by excess B12 and vice versa (they must be balanced) Vitamin B12 has a second role which is to help synthesize nerve tissue in the body, it is also a coenzyme in the production of nerve tissue myelin

What nutrients are added to enriched grains? (Recommend rereading pages 50-51 describing differences between enriched, un-enriched, and whole grains.)

Thiamin Niacin Riboflavin Iron

What does beri beri mean and how did it get its name?

Thiamin deficiency, Thiamin is involved in nerve and muscle processes and a deficiency results in beri-beri

Americans eat lots of polished rice; yet do not get beriberi, why?

Thiamin is available in other forms in our diet

Water-Soluble Vitamins and Coenzyme Names

Thiamin→ TPP Riboflavin→ FAD and FMN Niacin→ NAD and NADP Biotin→ Biotin Pantothenic acid→ Coenzyme A Folate→ THF Vitamin B12→ Vitamin B12 Vitamin C→ No coenzyme

A group of rats were fed a diet with inadequate amounts of all essential nutrients except niacin. They grew just as well as the control rats that were fed all nutrients including niacin. Niacin is still considered an essential nutrient for humans. Why? (Hint: think protein.)

Tryptophan can be used to make niacin

Why is there a UL for niacin? If someone consumes a large dose of niacin, what is the resulting reaction called? Note that the UL reflects quantity in a supplement rather than niacin in food.

UL for niacin? 35 mg/day Why? Large doses from supplements can overwhelm the body and raise blood concentrations to abnormally high levels Resulting reaction from consuming a large dose of niacin? Niacin flush, which dilates capillaries and causes a painful, tingling sensation

examples of Vision

Vit A

examples of bone health

Vit D Vit K Vit A

examples of Blood Clotting

Vit K

Why are elderly at risk for B12 deficiency (pernicious anemia)?

Why are the elderly at risk for B12 deficiency? They develop atrophic gastritis which damages stomach cells and cause HCl and IF production to diminish which leads to B12 deficiency even with proper food intake (pernicious anemia)

Why is there no pantothenic acid deficiency in the US? What is the role of pantothenic acids; specifically what enzyme requires pantothenic acid as part of its structure.?Biotin is needed to keep the TCA cycle going by making oxaloacetate from pyruvate as well as for other metabolic needs such as fatty acid metabolism. We get biotin from two sources; explain.

Why is there no deficiency in the US? Pantothenic Acid is widespread in foods and the typical diet provides adequate intakes Role? Specifically, what enzyme requires Pantothenic Acid as part of its structure? It is part of coenzyme A (CoA that forms acetyl CoA= the "crossroad" compound in several metabolic pathways What two sources do we get Biotin from? Obtained through a variety of food sources in the diet or can be synthesized by GI tract bacteria

roles of vitamins by funtion

antioxidants (AOX) bone health Blood Clotting coenzymes DNA synthesis Vision

examples of DNA synthesis

folate vit B12

examples of coenzymes

thiamin riboflavin niacin biotin pantothenic acid

examples of antioxidants (AOX)

vit E vit C Carotenoids

vitamins are divided into 2 categories

water soluble fat soluble