Chapter 8 notes: water-soluble vitamins

folate and vitamin B12 interaction:

THFA is active folate and methyl THFA is inactive folate

supplements cannot replace food

even a pill that meets all vitamin needs doesn't provide the energy, water, protein, minerals, fiber, or phytochemical that would have been supplied by food sources of these vitamins.

meeting vitamin needs

some vitamins are absorbed in inactive provitamin or vitamin precursor forms that must be converted into active forms by the bdoy

recommended vitamin B6 intake

- Adult DRI RDA: 1.3 mg/day for both men and women 19-50 years of age. - DRI UL is 100 mg/day from food and supplements. - Toxicity from excessive B6 from supplements • Peripheral nerve damage • Despite the dangers of taking excessive doses of B6 the vitamin is highly marketed to consumers.

recommended vitamin B12 intake

- Adult RDA: 2.4 micrograms/day - No UL and supplements of 500-1000 micrograms (mega doses) used for people who don't produce intrinsic factor (passive diffusion).

recommended folate intake

- Adult RDA: 400 micrograms DFE/day for adult men and women - During pregnancy, the RDA for folate is 600 micrograms/day - DRI UL is set at 1000 micrograms/day from supplements and/or fortified foods

recommended vitamin C intake

- Adult RDA: 75-90 mg/day - Cigarette smoking increases the requirement (because vitamin C is used to break down compounds in cigarette smoke) - The EAR is based on amounts in white blood cells - used to fight infections - antiviral effect. - UL is 2000 mg/day from food and supplements - abdominal problems (relatively non-toxic)

folate toxicity

- Although there is no known folate toxicity, a high intake may make the early symptoms of vitamin B12 deficiency.

vitamin B12 deficiency

- Atrophic gastritis may lead to B12 deficiencies. - The deficiency disease associated with B12 deficiency is pernicious anemia. Pernicious anemia is a form of anemia that doesn't respond to iron supplementation; usually caused by a lack of intrinsic factor, a protein needed for the absorption of the vitamin. The disease was always fatal before B12 supplements were available. - Pernicious refers to the brain damage because nerves don't have myelin sheaths; this is associated with the megaloblastic or macrocytic anemia because with low vitamin B12 folate is trapped in the inactive form (secondary deficiency of folate).

vitamins in our diet

- B vitamins were originally thought to be one chemical substance but are actually many different substances. this is the reason for B1, B2, B6, and B12. - today on B6 and B12 are still named as numbered. - the last of the 13 vitamins was characterized in 1948.

bioavailability of vitamins

- Bioavailability refers to how readily a nutrient can be absorbed and utilized by the body. - Vitamins must be absorbed by the body in order to perform their functions - Approximately 40-90% of vitamins are absorbed in the small intestine. - Fat-soluble vitamins require fat in the diet to be absorbed. - Water-soluble vitamins may require transport molecules or specific molecules in the GI tract.

how biotin functions in the body

- Biotin functions as a coenzyme in energy metabolism - Biotin functions as a coenzyme for a group of enzymes that add COOH to molecules. - Biotin helps form oxaloacetate (OAA) from pyruvate and metabolize glucogenic amino acids.

recommended biotin intake

- Biotin has an AI of 30 microgram for adult men and women

beans and tortillas provide niacin

- Corn-based diets are low in tryptophan and the niacin in corn is not well absorbed (bound). - The treatment of lime water during the preparation of tortillas improves niacin bioavailability. - Serving tortillas alongside beans (good sources of niacin) has helped prevent pellagra in countries with a corn-based diet (i.e. Mexico)

pantothenic acid deficiency

- Deficiency is rare. No UL and mixed results have been reported after supplementing with 10+ grams/day for several weeks.

causes lack of B12

- Dietary: B12 is strictly an animal product so it might be a problem for a strict vegetarian - Lack of intrinsic factor: people over age 50 are more susceptible to atrophic gastritis, an autoimmune disorder that results in lower or no levels of intrinsic factor being secreted. - Crohn's disease: Absorption problems in the ileum: interfering with absorption of the B12 - IF complex.

storage and excretion

- Except for vitamin B12 water-soluble vitamins are not stored in the body tissue pools and are readily excreted in the urine. - Fat-soluble vitamins are stored in adipose tissue and liver, but are not excreted in the urine to any great extent; they are removed from the body by being excreted in bile. - This there is a greater risk of deficiency with water-soluble vitamins, but greater risk of toxicity for fat-soluble vitamins.

vitamin B12 toxicity and supplements

- Excessive intake of folic acid can mask B12 deficiencies - Vegan diets need to be supplemented with readily absorbable forms of B12.

folate functions in the body

- Folate coenzymes are needed for DAN synthesis, formation of red blood cells, and the metabolism of some amino acids.

folate in the diet and digestive tract

- Folate is the form found naturally in food; it includes many glutamate molecules [Glu] attached to form a chain. All but one glutamate must be removed before the folate can be absorbed. - Most forms in foods have a string of glutamates attached - Since 1998, enriched grain products have been fortified with folic acid

Vitamin B6 in the diet

- Found in both animal and plant foods - Meat, legumes, and whole grains - Grain products without enriched vitamin B6, but fortified breakfast cereals are important contributor to diet. - Easily destroyed by exposure to heat and light and is easily lost in processing.

how antioxidants work

- Free radical: one type of highly reactive molecule that causes oxidative damage - Oxidative damage - damage caused by highly reactive oxygen molecules that steal electrons from other compounds, causing changes in structure and function. - Without vitamin C, free radicals can damage DNA and other molecules - Vitamin C neutralizes free radicals so they can no longer damage molecules such as DNA.

is frozen really fresh

- Frozen foods are often frozen in the field in order to minimize nutrient loss. Thus, frozen fruits and vegetables may supply more vitamins than fresh ones - The high temperatures used in canning reduce nutrient content. However, because canned foods keep for a long time, do not require refrigeration, and are often less expensive than fresh or frozen foods, they provide an available, affordable source of nutrients that may be the best choice in some situations. - Sometimes "fresh" produce is lower in nutrients than you would expect because it has spent a week in a truck, traveling to your store, several days on a shelf, and maybe another week in your refrigerator.

biotin in the diet

- Good dietary sources: liver, egg yolks, yogurt, and nuts. - While fruit and meat are poor sources. - Avidin in raw eggs binds biotin. - Biotin was discovered when rats were fed protein derived from raw egg white and developed hair loss, dermatitis, neuromuscular dysfunction. - Cooking eggs denatures the protein avidin found in egg whites; when raw egg whites are consumed, avidin acts as an anti-vitamin by binding to biotin and preventing its absorption. • Drinking raw eggs is common among body builders. • Cooking eggs provide just as much protein and do NOT reduce biotin absorption or pose a risk for Salmonella infection.

B12 and folate

- If sufficient quantities of folic acid are provided in fortified foods or supplements, the anemia due to folic acid deficiency can be prevented but the neurological symptoms that are directly due to vitamin B12 deficiency cannot. - Vitamin B12 deficiency causes folate deficiency because it prevents folate from being converted into the active form that is needed for DNA synthesis. - The secondary folate deficiency can cause macrocytic anemia.

vitamin B6 deficiency

- May result in anemia due to impaired hemoglobin synthesis and neurotransmitter issues - Without this vitamin, non-essential amino acids cannot be synthesized. - Deamination reactions remove the amino groups from amino acids so they can be used to produce ATP or to synthesize glucose. -- > ATP production and glucose synthesis. - Decarboxylation reaction: decarboxylation reaction removes the acid group (COOH) from amino acids so they can be used to synthesize neurotransmitters. - Neurological symptoms of B 6 deficiency include: depression, headache, confusion, numbness, and tingling of the extremities and seizures. - Vitamin B6 deficiency symptoms may also include: poor growth, skin lesions, decreased antibody formation. - Affected by a number of drugs including: alcohol and oral contraceptives - Alcoholics have an increased need for B6.

vitamin B12 in the digestive tract

- Most readily absorbed from animal products 1. Vitamin B12 in food is bound to protein 2. In the stomach, acid and pepsin release vitamin B12 from food proteins. In stomach, B12 binds to R protein. 3. Parietal cells in the stomach lining release intrinsic factor (IF). 4. In the upper portion of the small intestine (duodenum), intrinsic factor binds to vitamin B12. 5. In the lower part of the small intestine (ileum), the vitamin B12- intrinsic factor complex binds to receptors on cells, allowing absorption in large doses. 6. In the colon, vitamin B12 is synthesized by microorganisms but cannot be absorbed.

how vitamin B12 functions in the body

- Needed for healthy red blood cells and healthy nerve cells. - Necessary for the proper absorption of iron in the body

how niacin functions in the body

- Niacin plays an important role in the production of energy and in general metabolism - Two forms of niacin are nicotinic acid and nicotinamide. - Two active coenzymes that contain niacin re : nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP). - Two forms of niacin in the body: • NAD is a carrier of electrons and hydrogens taken from energy macronutrients and alcohol in catabolism. • NADP has the same role, but acts in synthesis reactions such as fatty acids synthesis from glucose.

niacin toxicity and supplements

- Niacin toxicity from overuse of niacin supplements can result in elevated blood pressure, cardiac arrhythmia, nausea vomiting, elevated blood sugar levels, and impaired liver function, flushing of skin, tingling sensation in the hands and feet, a red skin rash, and blurred vision. - There is no evidence of adverse effects from consumption of niacin in foods.

riboflavin toxicity and supplements

- No toxic effects have been observed from excessive intake of riboflavin and there is no DRI UL. Extra riboflavin is quickly eliminated in urine and the urine turns bright yellow. - In the absence of a deficiency, riboflavin supplements don't increase energy or cure eye diseases and skin disorders

biotin toxicity

- No toxicity has been reported and no DRI UL exists. - Biotin deficiency is uncommon.

thiamin toxicity and supplement

- No toxicity has been reported with excessive intakes of thiamin and there is no DRI UL. - Thiamin supplements above requirements don't increase "energy levels" nor improve mental function nor prevent heart disease.

does vitamin C cure the common cure?

- No. - Vitamin C supplementation can reduce the duration and severity of colds, but apparently not the number of colds; supplementation must begin before contraction of cold. - Little evidence to support reduction of CVD - Vitamin C and cancer prevention may be due to consumption of fruits and vegetables with a variety of nutrients and other harmful substances.

how pantothenic acid functions in the body

- Pantothenic acid is part of the coenzyme A (CoA) molecule, which is part of acetyl CoA. - Pantothenic acid is also needed to produce acyl carrier protein needed for synthesis of cholesterol and fatty acids.

niacin deficiency

- Pellagra - characterized by progressive physical and mental deterioration - Pellagra was first observed in Europe in the 1700s and became widespread in Southeastern US in early 20th century where corn was a dietary staple. - Dr. Joseph Goldberger demonstrated that pellagra was not an infectious disease, but the problem not corrected until refined grains were enriched in the 1940s. - Initial deficiency symptoms of Pellagra include: fatigue, decreased appetite, and indigestion. - As deficiency progresses, the three D's develop: • Dermatitis: the cracked, inflamed skin characteristic of pellagra most commonly appears on areas exposed to sunlight or other stresses. • Diarrhea • Dementia • If left untreated - the fourth D is death

How vitamin B6 functions in the body

- Pyridoxal, pyridoxine, and pyridoamine (all forms of vitamin B6) can be converted into the coenzyme for, pyridoxal phosphate, which is required for more than 100 enzyme reactions in the body. - It is involved with protein, carbohydrate, and fat metabolism. - Maintains blood concentrations of blood pyridoxal phosphate. - Vitamin B6 is distinguished from other B vitamins but its role in amino acid metabolism (transamination and deamination: helps move NH2 group). • Transamination reactions synthesize nonessential amino acids by transferring an amino group to a carbon compound. - It is needed to synthesize hemoglobin, form white blood cells, convert tryptophan to niacin, metabolize glycogen, synthesize certain neurotransmitters and lipids for the myelin sheath (insulation) of many nerves. - Both vitamin B6 and B12 are required for myelin formation, which is needed for normal nerve transmission for most nerves.

Vitamin C functions in the body

- Required for the production of collagen - Works as an antioxidant - helps maintain the immune system - Promotes absorption of iron - Participates in amino acid metabolism - Required for the synthesis of steroid hormones, such as thyroid hormone, bile acids, and carnitine needed for fatty acid oxidation.

vitamin preservation

- Store food away from heat and light, and eat it soon after purchasing it. - Cut fruits and vegetables as close as possible to the time when they will be cooked or served. - Don't soak vegetables. - Cook vegetables with as little water as possible by microwaving, pressure-cooking, roasting, grilling, stir-frying, or baking rather than boiling them. - If foods are cooked in water, use the cooking water to make soups and sauces so that you can retrieve some of the nutrients. - Don't rinse rice before cooking in order to avoid washing away water-soluble vitamins.

how thiamin functions in the body

- The active thiamin coenzyme is needed to convert pyruvate into acetyl CoA. Acetyl CoA can be used to produce ATP or to synthesize the neurotransmitter acetylcholine. - Without thiamin, the body cannot synthesize acetylcholine or properly use glucose, which is the primary fuel for the brain and nerve cells. - Thiamin is a vitamin, so it doesn't provide energy but its important in energy metabolism (Active form: thiamin pyrophosphate) - Thiamin is also needed for the metabolism of other sugars and certain amino acids; the synthesis of the neurotransmitter acetylcholine

vitamin C deficiency

- The symptoms of scurvy may appear. These symptoms reflect the role of vitamin C in the maintenance of collagen. - Like other body proteins, collagen is continuously broken down and reformed. Without vitamin C, the bonds holding adjacent collagen molecules together cannot be formed. • The inability to form healthy collagen prevents wounds from healing normally and causes bone and joint aches, etc.

recommended pantothenic acid deficiency

- There is no DRI RDA but an AI of 5 mg/day has been recommended for adult men and women.

water soluble vitamins - B vitamins - vitamin C

- Thiamin (B1) - riboflavin (B2) - niacin (B3) - biotin - pantothenic acid - vitamin B6 - folate - vitamin B12

absorption of vitamins

- Thiamin and vitamin C have energy-requiring transport systems. - Niacin and riboflavin also require carrier proteins - B12 must be bound to a protein in the stomach for absorption in the small intestine. - Some water-soluble vitamins have transport systems for absorption. - Majority of absorption occurs in the small intestine.

thiamin deficiency

- Thiamin converts pyruvate into acetyl-CoA. - The deficiency disease present, for over 1000 years in East Asia, is called beriberi. It occurred when people consumed white rice as the staple of their diets. - Beriberi refers to the extreme weakness and depression that are the earliest symptoms of the disease. - Scientists thought it was an infectious disease until Eijkman noticed that chickens fed white rice polished rice developed the disease and got better when fed brown rice. - Symptoms of beriberi include: lethargy, fatigue, other neurological symptoms, rapid heartbeat, enlargement of the heart and congestive heart failure. - Alcoholics have an increased risk of thiamin deficiency. - A deficiency of thiamin in alcoholics is called Wernicke-Korsakoff syndrome. - Thiamin deficiency is readily reversible.

biotin deficiency

- Uncommon, although it can be observed in people with malabsorption or protein-energy malnutrition, those receiving tube feedings

recommended niacin intake

- Unlike the previous B vitamins covered there is a DRI UL for niacin (35 mg). - Doses of 50 mg/day of nicotinic acid are given to patients with cardiovascular disease to lower LDL cholesterol and triglycerides and raise HDL cholesterol.

vitamin B12 in the diet

- Vitamin B12 is part of two active coenzymes called methylcobalamin and adenosylcobalamin. - These coenzymes participate in the reaction moving proportionate to succinate (citric acid cycle intermediate) and homocysteine to methionine.

how vitamin B6 status is related to cardiovascular disease

- Vitamin B6, folate, and Vitamin B12 are required in the metabolism of homocysteine. Without adequate amounts of these B vitamins, homocysteine accumulates and increases risk of cardiovascular disease.

Vitamin C in the diet

- Vitamin C in foods can be destroyed by oxygen, light and heat, as well as contact with copper or iron cookware. - Citrus fruit, broccoli, strawberries, leafy green veggies, peppers. - Lemons and lime - British called "limeys"

niacin recommendations

- adult RDA: 14-16 mg NE/day - RDA is in terms of niacin equivalents because we can make niacin from tryptophan. - niacin can be synthesized in the body from the essential amino acid tryptophan if the diet is low in tryptophan. - we consume both niacin and the essential amino acid tryptophan in our diet. tryptophan can be used to synthesize niacin but only after the need for tryptophan in protein synthesis has been met. the diet provide food sources of both niacin and tryptophan - tryptophan - protein synthesis: dietary tryptophan must first meet the need for protein synthesis - tryptophan - niacin: once the need for tryptophan in protein synthesis has been met, the extra can be used to meet th need for niacin; 60 mg of tryptophan can synthesize 1 mg of niacin

riboflavin deficiency

- ariboflavinosis. symptoms include inflammation of the eyes, lips, mouth, tongue, scaly greasy skin eruptions, cracking of the tissue in the corners of the mouth and confusion. - deficiency of riboflavin alone is rare. Usually multiple B vitamin deficiencies occur together because food sources of B vitamins are similar.

dietary supplements

- can be another source of vitamins in the modern diet - contain some combination of vitamins, minerals, herbs, botanicals, amino acids, enzymes, or extracts. - cannot replace the benefits of a diet containing a wide variety of foods - most common vitamin deficiencies in the past have been eliminated. - vitamin A deficiency remains a problem in developing countries. - certain segments of the U.S. population, children, pregnant women, alcoholics, and the elderly are at risk for deficiencies. - the big question is what is an optimal amount for each nutrient.

provitamin (precursor)

- chemical compound closely related to a vitamin in structure - the body is capable of converting an inactive provitamin into the chemical structure that is the vitamin

history of vitamins

- discovery of vitamins began in 1897. - Eijkman noticed that a diet of polish rice read to the disease beriberi - new industries have appeared which have capitalized on vitamins as the great panacea. - in truth - the only disease that caused by a deficiency of that vitamin.

enriched foods

- enrichment: describes adding nutrients [B vitamins - thiamin, riboflavin, niacin, and iron] back to foods that have lost nutrients due to processing. - an example is the addition of B vitamins to white rice.

folate deficiency: heart disease

- folate deficiency impacts the metabolism of the amino acid homocysteine.

fortified foods

- fortification: process of adding nutrients to foods. the added nutrients are generally not found in the food in its natural form or are added in much larger amounts. - an effective way to supplement nutrients that are deficient in the populations diet without having to rely on consumers to alter their food choices or to take nutrient supplements. - examples of fortification: calcium added to orange juice, vitamin D added to milk, iodine added to salt, some breakfast cereals are so highly fortified that stye are almost the same as a vitamin-mineral supplement. - enough or too much: almost all breakfast cereals are fortified with iron and calcium and a complement of vitamins, many of which are not deficient in the U.S. diet. - fortification doesn't necessarily make a food a better food.

folate deficiency: cancer

- low folate status is associated with increased risk for ovarian, breast, pancreas, and colon cancers

riboflavin in the diet

- milk (best source in North america) - plant sources include: mushrooms, broccoli, asparagus, whole grains and green, leafy vegetables - animal sources: milk, red meat, poultry, fish - milk doesn't come in glass bottles anymore because riboflavin is easily destroyed by light (and heat). Exposure to light can also cause an "off" flavor in the milk and losses of vitamin A and D.

niacin in the diet

- niacin is still added to enriched flours in North America - beef, chicken, peanuts, and legumes - whole and enriched grains

coenzyme function (B vitamins)

- primary function: energy metabolism - Coenzymes are needed for enzyme activity. They act as carriers of electron, atoms, or chemical groups that participate in the reaction. - All the B vitamins are coenzymes, but there are also coenzymes that are not dietary essentials and therefore are not vitamins 1. The vitamin combines with a chemical group to form the functional coenzyme (active vitamin). 2. The functional coenzyme combines with the incomplete enzyme to form the active enzyme. 3. The active enzyme binds to one or more molecules and accelerates the chemical reaction to form one or more new molecules. 4. The new molecules are released, and the enzyme and coenzyme (vitamin) can be reused or separated.

finding vitamins in food

- processing, storage, and cooking can affect vitamin levels in food. - processing can also ADD vitamins to food.

because vitamin C can serve as a reducing agent, they can donate electrons

- reversible reaction - vitamin C can be restored

RIBOFLAVIN

- riboflavin as discovered along with other B vitamin, while searching for a cure to beriberi

how riboflavin functions in the body

- riboflavin is part of two active coenzymes called flavin adenine dinulceotide (FAD) and flavin mono nucleotide (FMN). - riboflavin is an important component in the citric acid cycle, electron transport system, and assists in the conversion of other vitamins (folate, niacin, B6, vitamin K) into their active forms.

THIAMIN (B1)

- thiamin was the first B vitamin to be identified and is also called B1 - thiamin assists in energy production, carbohydrate metabolism, the production of ribose, and the health of the nervous system. - a deficiency of thiamin is called beriberi.

pantothenic acid in the diet

-widespread in foods - AI: 5 mg/day - its abundant in meat, eggs, whole grains, and legumes.

meeting folate needs

Calculating dietary folate amounts • The folate listed on labels or fortified foods is primarily folic acid, which is more available than normal forms of folate. In order to compare the folate content of these foods to recommendations, the amount of folic acid must be converted to dietary folate equivalents, expressed as micrograms DEF. • Determine the amount of folic acid in the fortified food: multiply the daily value for folate by the % daily values listed on the label. Daily value is 400 micrograms. • Convert micrograms folic acids into micrograms DFE: multiple the microgram folic acid by 1.7. Folic acid added to a food in fortification provides 1.7 x more available folate per microgram than folate naturally present in food.

What do vitamins do?

Vitamins promote and regulate body functions: - Vitamins don't provide energy, but are required to obtain energy from energy macronutrients and alcohol (thiamin, riboflavin, niacin, pantothenic acid, and biotin) Function as co-enzymes (B vitamins): - Play an important role in amino acid and protein metabolism (vitamin B6) - Ensure normal cell division (folate and vitamin B12) - Coenzyme for synthesis of neurotransmitters, hormones, and a protein vital for collagen formation and bone health. - Vitamin K is fat-soluble coenzyme needed for proper blood clotting. - Vitamin D and vitamin A bind to receptors that influence gene transcription (transcription factors) - Vitamin A also binds to a protein in the eye so light can be sensed by the brain for vision

vitamin

a potent, indispensable, non-caloric, organic compound needed in very small amounts in the diet that perform specific and individual functions to promote growth, reproduction, or maintain life .

thiamin in the diet

adult RDA: 1.1-1.2 mg/day - commonly found in pork, lentils, sunflower seeds, and bread. - thiamin is widely available in foods, especially in enriched grains, whole grains, legumes, nuts, and seeds. - thiamin in food is sensitive to heat (may be destroyed by cooking), oxygen and low acid conditions and there are anti-thiamin enzyme factors in raw seafood and binding factors in other foods that block absorption.

VITAMIN B6

also called pyridoxine and compromises a group of compounds including pyridoxal, pyridoxine, and pyridoxamine

antivitamin

an antagonist to a vitamin, which can replace the vitamin in chemical reactions

vitamin B6 toxicity and supplement

can cause irreversible nerve damage

CHOLINE

choline is group with B vitamins, but your book doesn't include it as a vitamin. - needed for synthesis of phosphatidylcholine, a phospholipid, and major components of cell membrane, and acetylcholine (a neurotransmitter) - choline can be synthesized to some extent. - good sources are egg yolks, organ meats, spinach, nuts, and wheat germ. - AI of 550 mg/day for men and 425 mg/day for women (this means its a required nutrient). - a UL for adults of 2.5 g/day result in hypotension (low blood pressure)

VITAMIN B12

cobalamin is the chemical name

FOLATE (FOLIC ACID)

folate and folacin are general terms for many forms of the vitamin named after the Latin word for foliage. - folic acid is the form of folate that has only one molecule of glutamate. it is easily absorbed and this is the form found in fortified foods and supplements - bioavailability of synthetic ~2x that of natural forms.

pantothenic acid toxicity

not common

VITAMIN C

vitaminC is also known as ascorbic and ascorbate. Vitamin C = colorful history - Scurvy is one of the oldest known deficiency disease - James Lind demonstrated that sailors provided oranges and lemons were cured of scurvy. - Vitamin C is required by only a few species: man, monkey, guinea pig, a bid called the bulbul and the trout.

super fortified foods

whether they are healthy or harmful depends on what is in them and how much you consume

folate deficiency: neural tube defects

• Folate deficiency early in pregnancy is associated with an increased risk of neural tube defects. • Neural tube defects include spina bifida, anencephaly, and other birth defects that affect the brain and spinal cord. • Spinal bifida occurs if a lower portion of the neural tube doesn't close normally • Anencephaly = If the head end of the neural tube doesn't close properly, the brain doesn't form completely • Neural tube closure occurs by 28 days after conception so folate status needs to be adequate before pregnancy. • It appears that low folate coupled with a genetic predisposition is the problem. So, it is not strictly a folate deficiency. • Since enrichment of grains NTD down 50% in U.S.

folate deficiency: microcytic anemia

• Folate is needed for cells to divide. In folate deficiency, cells that develop into mature red blood cells cannot duplicate their DNA and divide These immature cells called megaloblasts, are converted into large red blood cells called macrocytes. Fewer RBCs are produced and the oxygen carrying capacity of the blood is reduced. • Cannot duplicate DNA. When cells are unable to divide it leads to a macrocyte.

how vitamin C functions in the body : collagen

• Reactions requiring Vitamin C = essential for formation of bonds that hold adjacent collagen strands together and give protein strength and stability • Wound healing. • A deficiency can lead to scurvy • The gums become inflamed, swell, and bleed. Teeth become loose and eventually fall out. • Collagen molecules with no vitamin C: weak abnormal connective tissue. • Collagen molecules with vitamin C: strong, healthy, cross-linked connective tissue.