hnsc 1210 unit 7: the vitamins

vitamins

• organic compounds that are vital to life ad indispensable to body functions

• only needed in minute amounts, and are non-caloric, essential nutrients

2 classifications for vitamins

1. fat soluble

2. water soluble

what are the fat soluble vitamins

• vitamin A

• vitamin D

• vitamin E

• vitamin K

water-soluble vitamins

B vitamins

• Thiamine (B1)

• Riboflavin (B2)

• Niacin (B3)

• Folate

• Vitamin B12

• Vitamin B6

• Biotin

• Pantothenic acid

Vitamin C

fat soluble vitamins

• dissolve in lipid and required bile for absorption

• absorbed into the lymph and travel through the blood with protein carriers

• stores in liver or with other lipids in fatty tissues and can build in toxic amounts - use with caution with fat soluble vitamin supplements

Vitamin A

• first fat soluble vitamin recognized

three active forms of vitamin A

1. retinol is stored in the ivermectin and the body’s cells convert retinol to the other two active forms;

2. retinal and

3. retinoids acid as needed

b-carotene

• found in plant based foods

• can be converted to vitamin A

• precursor to vitamin A

• considered to be an antioxidant

• takes approx 12ug b carotene to supply 1st of retinol

vitamin A functions

• gene expression

• vision

• maintenance of epithelial tissue

• immune defences

• growth of bones

• reproduction

vitamin a function: gene expression

• regulates activities of genes, which direct the synthesis of proteins such as enzymes. vit a helps to activate or deactivate certain genes, thus affection the production of specific proteins

vitamin a functions with vision

• plays 2 roles: a. process of light perception in the retina, b. maintenance of cornea

• part of rhodopsin molecule (light sensitive pigment cells in the retina)

• a. if deficient, night blindness can occur (lag before the eye can see again after a bright flash of light)

• b. if deficient keratin (protein normally found in hair and nails) can accumulate and cloud the cornea, leading to a condition called keratinization

• if vitamin a deficiency continues, it can lead to drying of the cornea (xerosis) and then progress to xerophthalmia (thickening of the coronet and permanent blindness)

vitamin a function: maintenance of epithelial tissue

• involved in the cell differentiation and maturation process

• each type of cells develops to perform a specific function

• skin and al protective linings of the lungs, intestines, urinary tract, bladder, etc. all rely on vit a to ensure proper developed and replacement of cells

vitamin a: growth of bones

• in children, old bone structures as dismantled by the body and remodeled into large bone parts

• vitamin a plays important tole in the dismantling process - without it, bone growth cannot take place

vitamin a: reproduction

• because of vitamin a’s role in cell differentiation and maturation

food sources

• active vitamin A is in richest sources of animals

• liver and fish oils

• milk and fortified foods like cereal

• plans contain no active vitamin a

• deep orange and green plants have the precursor

• precursor or provitamin, once inside the body can be converted into active vitamin a form - not that efficient

• salad with carrots and cheese would be a good source

vitamin a and beta carotene snapshot

vitamin A deficiency

• prevalent in devoting countries

• b/w 3-10 million holders throughout the world suffer from signs of severe vitamin a deficiency

• in countries were children receive vitamin a supplements, childhood death rates have been cut in half

symptoms of vitamin a deficiency

• blindness, night blindness, xerosis

• impaired bone growth, easily decayed teeth

• lowered immune function

• keratin lumps on skin: because cells do not mature – instead, they die off and secrete keratin.

vitamin A toxicity

• seen from supplements and fortified foods

• only food that is a natural source of vitamin a can cause toxicity is liver; including fish livers, and the liver of animals that eat whole fish (e.g polar bears)

• chronic intake of even small excesses of vitamin a can weaken the bones and contribute to hip fractures

why should pregnant women be cautious with vitamin A

• chronic use of vitamin A supplements at high doses can cause malformations of the fetus

vitamin A toxicity symptoms

• stunted growth, muscle/bone pain, edges

• fatigue, blurred vision, headaches, loss of menstration

• abdominal pain, anorexia, nausea, diarrhea

• skin disorders, rashes, itching, hair loss

• liver damage, enlargement of spleen

beta carotene not converted efficiently enough to retinal to cause toxicity symptoms

• it has been known to turn people’s skin bright orange/yellow

• beta carotene builds up in the fat beneath the skin

• this looks alarming, however is harmless

• concentrated beta carotene supplements may have adverse effects however, such as increased risk of lung cancer in those who smoke

other forms of vitamin A

• retinoids acid can be used as a dug, directly applied to the skin resulting in rapid turnover of skin cells

• retin-A: used for acne; renova: used as anti-wrinkle product

• supplementing vitamin A does not help acne. accurate is derived from vitamin A, but is chemically altered and given in controlled doses

• all of these forms are highly toxic and at risk for causing serous brith defects if taken using pregnancy

vitamin D

• chemical name is cholecalciferol

vitamin D functions

• plays a role (along with a number of other nutrients and hormones) in regulating blood calcium and phosphorus levels - thereby maintaining bone integrity

• when blood calcium levels are low, vitamin D acts on the skeleton, the digestive tract and the kidneys to raise blood calcium levels

• functions as a hormone and plays roles in the workings of the brain, heart, stomach, pancreas, skin, cells of the immune system, and reproductive organs by stimulating cell maturation

vitamin D food sources

• Fortified milk and margarine, eggs, butter, and fish. More foods are starting to be fortified with Vitamin D (e.g., yogurt).

sunlight

• UV light from the sun inverts cholesterol compounds in human skin into a vitamin D precursor and is directly absorbed into the blood

• liver and kidneys then finish converting the precursor to active vitamin D

the duration of UV light exposure is needed is specific to race

• fair skinned individuals may need exposure of facial area for 10-15 minutes 3-7 days per week to synthesize required levels of vitamin D, whereas darker-skinned individuals may need upwards of 3 hours.

• Latitude also plays a role: in Manitoba, we typically only have the strength of the sun needed to synthesize vitamin D between April and October.

• During the winter months, we rely on our liver stores.

factors effecting sun exposure

• affects sun exposure and vitamin D synthesis: UV rays cannot penetrate clouds, smog, heavy clothing, window glass, window screens

• some screens prevent sun rays exposure

• time of day - mid day gives us maximum direct sun exposure

• lifestyle - working indoors, older adults are homebound

• use sun screen - limit exposure

• go outdoor for 15 mins then put on sunscreen after to get adequate vitamin D synthesis

• too much exposure does not affect vitamin D synthesis but can result in skin cancer

vitamin D deficiency

• two forms: rickets and osteomalacia (bone disease in children and adults, respectively)

vitamin d deficiency: rickets

• children developed bowed legs due to weakened bones to support body weight

• develop knobs/beads on the ribs

• condition is fairly uncommon in developed countries today, however is sometimes seen if a child is not provided with adequate dietary vitamin D (e.g fed soy/rice beverage hat is not fortified with vitamin D o replace cow’s milk which is fortified), and in children in developing countries

vitamin d: osteomalacia

• adult form of vitamin D deficiency

• can occur in women with repeated pregnancies who have low calcium intake, little sun exposure and breast feed multiple children

• calcium is withdrawn from the bones, as a result he bones in the legs and spine soften and the person becomes bowlegged and stooped

• research is hinting that vitamin D deficiency may be linked to many problems such as high blood pressure, some type of cancer, diabetes, heart disease, rheumatoid arthritis, inflammatory bowel disease, even multiple sclerosis

• well established problems concern impairment of calcium and the bones

the risk of vitamin D deficiency increases with age due to a number of factors

• lower intake, housebound (so little UV light exposure), decreased ability to activate vitamin D, and our need for vitamin D increases after the age of 50

vitamin D toxicity

• out of all the vitamin, vitamin D is the most potentially toxic

• toxicity is squally seen from supplements

vitamin D toxicity symptoms

• appetite loss, nausea/vomiting, increased thirst & urination, severe psychological depression (because of the effects on the central nervous system)

vitamin D long term toxicity

• Vitamin D raises the blood mineral levels dangerously high, resulting in calcium deposits in the soft tissues of the heart, blood vessels, lungs and kidneys, which can lead to serious malfunctions and even death.

• There is a case discussed in your textbook where two people died after drinking milk from a dairy that accidentally over fortified the milk with 500 times the usual dose of Vitamin D.

vitamin E

• active form s tocopherol

• alpha is the gold standard, therefore DRI is expressed as alpha-tocopherol

vitamin E function

• acts as an antioxidant, serves as the body main defenders against oxidative agents.

• important in red blood cells because they are exposed to high levels of oxygen

• white blood cells depend on vitamin e - therefore may play a role in immunity

• previous research as shown hope that supplements help heart diseases, but recent studies don’t show this

• too much vitamin e intake can be harmful to health

free radical damage and antioxidant protection

vitamin E food sources

• Vitamin E is found wide-spread in foods (e.g., vegetable oils [canola, safflower, sunflower], vegetables and fruits, fortified cereals/grains, meat and alternatives, and milk products). Heat processing destroys Vitamin E, so most processed, fast foods, deep fried foods and convenience foods retain little intact vitamin E.

vitamin E deficiency

• Vitamin E deficiency is rare because of three things:

1. Vitamin E is widespread through foods.

2. The body stores enough vitamin E in fatty tissue to last a long time.

3. The cells recycle their working supply of vitamin E, using the same molecules over and over again.

vitamin e deficiency increases premature infants

• may occur in premature infants born before transfer of vitamin e from mother to baby (thought to occur in the last quarter of pregnancy, from 30 weeks on). without sufficing vitamin E, the infants’ red blood cells rupture (erythrocyte hemolysis) and the infant becomes anemic

vitamin e deficiency increases adults

• may be associated with diseases that cause fat malabsorption (e.g., injury/disease of the liver, the gallbladder or the pancreas). The symptoms sometimes seen in adults (weakness, impaired reflexes, impaired vision/speech) are caused by oxidative damage. Vitamin E treatment corrects them.

• Sometimes, Vitamin E deficiency can be seen if an extremely low fat diet is being followed long term (over a few years).

• Research is hinting that chronic low intake of vitamin E may play a role in disease development.

vitamins e toxicity

• rare

• no adverse effects have been reported from naturally occurring vitamin e in foods

• toxicity is more s seen from supplements and fortified foods

• supplements doses up to the DRI are generally safe, doses beyond are risky. research shows an increased risk death from all cases, compared to those taking smaller doses

• supplements also increase the effects of anticoagulant medications used to prevent unwanted blood clotting. this means the potential for an increased risk of uncontrollable bleeding

symptoms of vitamin e toxicity

• nausea

• fatigue

• Gi distress

• blurred vision

vitamin k functions

• main function is to help synthesize proteins that j help clot the blood

• anticoagulant medications (e.g warfarin/ coumadin) interfere with the action of the vitamin k in promoting clotting

vitamin K needed for synthesis of key bone proteins

• without vitamin k, the bones produce an abnormal protein that cannot bind to bone minerals, resulting is low bone density

• adequate vitamin k may reduce the risk of hip fractures that those with lower intakes

vitamin k sources

• like vitamin d, vitamin k can be derived from a non-food source - this time by our intestinal bacteria

• we normally have billions of bacteria residing in our colon, some which synthesize vitamin k, this production if affected by:

• absorption problems/illness

• antibiotic use

• both affect the bacteria residing in our colon, so we can result in decreased vitamin k production

vitamin k food sources

• richest plant food sources include dark leafy green veggies, spinach and coloured green, cabbage family

• vegetable oil like canola and vegetable

• beans and legumes

• fortified cereal

• reaches animal sure is liver, milk and eggs contribute small amounts

vitamin k deficiency

• few north american adults experience, exception may be people who have taken antibiotics that have killed harmful and the beneficial bacteria in their intestinal tract

• another exception is if a person has problems with fat absorption

• vitamin k supplementation would be requires, as vitamin k deficiency can b fatal.

• symptoms include: easy bruising and hemorrhaging

vitamin k deficiency is infants

• newborn infants are born with sterile intestinal tract, and the vitamin k producing bacteria take weeks to establish themselves

• therefore, to prevent hemorrhage the newborn is given a dose of vitamin k at birth

vitamin k toxicity

• rare reports in healthy adults, DRI no UL

• sometimes seen in infants and pregnant women, toxicity occurs when vitamin k supplements are given too eagerly

• toxicity causes the breakage of RBC and release of their pigment (bilirubin). the liver then releases the bilirubin into the blood instead of excreting it into the bile and this leads to jaundice. if bilirubin invades an infant’s brain this can lead to brain damage, even death

water soluble vitamins

• are the vitamin C and vitamin Bs

• dissolve in water, so they are absorbed directly into the blood stream where they travel freely

• most are not stored in the tissue to any great extent and excesses are excreted in the urine. therefore, there is less risk of immediate toxicities

vitamin c requirements

• not that much because if the vitamin c in our body is recycled back into the active form for reuse

• body’s pool of vitamin c overflows at around 100mg/d (meaning we will typically urinate out the rest)

smoking and vitamin c

• Smoking/tobacco introduces oxidants to our body that deplete the body’s vitamin C. Therefore, smokers need more vitamin C to maintain blood vitamin C levels similar to a non smoker (an additional 35 mg/d). Even being around second hand smoke can increase a person’s need for Vitamin C.

vitamin c functions

• best known for maintaining the connective tissue and as an antioxidant

vitamin c functions: maintenance of collagen/connective tissue

• collagen forms the base of all connective tissues including our bones, teeth, skin, and tendons

• it forms scar tissue to heal wounds, forms the reinforcing structure that mends fractures, and forms the supporting material of capillaries that prevent bruises

• vitamin c assists several enzymes in performing their task

• enzymes novices in the formation and maintenance of collagen (a tissue protein) rely on vitamin c for their activity

vitamin c function: antioxidant protection and immune function

• Vitamin C protects cells from oxidation by becoming oxidized itself (e.g., immune cells maintain high vitamin C levels to protect themselves from free radical damage when fighting bacteria and other invaders).

vitamin c functions: promotes iron absorption

• In the intestines, vitamin C protects iron from oxidation, therefore promoting its absorption.

vitamin c functions: assist with vitamin E recycling

• Vitamin C also helps to protect sensitive blood constituents from oxidation and helps to protect and recycle vitamin E to its active form.

vitamin c’s role as an antioxidant, research done to see if it can play a role in disease prevention

• however, research is finding the vitamin c appears useless against diseases such as heart disease and cancer unless there is a deficiency in vitamin C

vitamin c and the common cold

• no study to the current date has shown that vitamin c can prevent cold or reduce their severity

• some research showing that taking a therapeutic dose of vitamin c at the onset of a cold can reduce the length by a half day and the symptoms by 40%

• 1g of vitamin c a day is a therapeutic dose

• these effects may be greater in children than adults, they need close to UL 2.g

• placebo affect, one study gave participants half vitamin c and half a placebo, told each group they gave them opposite group, placebo group reported less colds than the ones who did get vitamin c

• if pearson things product it will treat them, it might

vitamin c food sources

• Fruits and vegetables are the key sources of vitamin C.

• The best sources are fresh, raw, and quickly cooked fruits, vegetables and juices, as vitamin C is vulnerable to heat and destroyed by oxygen.

• Therefore, foods should be properly stored and consumed promptly after purchase to maximize vitamin C content.

vitamin c deficiency

• 200 years ago people who went long seagoing ship only had 50% chance of survival because of scurvy. this is due to the cook using fresh veggies and fruits first of the voyage, leaving only grains and animals meats to survive on for the rest of the voyage. once discovered that citrus juice could cure scurvy, british navy required al vessels to provide lime juice to each sailor daily

• absorbing acid literally means “no scurvy acid”

• deficiency is now rare. sometimes seen in elderly (if lower food intake), alcohol/drug addicts, and in infants fed not cow’s milk as their fluid (no vitamin c fortified formula or juice. breast milk and formula provide vitamin c

• Most of the symptoms of scurvy are caused by the breakdown of collagen in the absence of vitamin C. We can also see anemia develop, because of vitamin C’s role in helping the body use and absorb iron. Vitamin C deficiency causes the breakdown of collagen, which supports the teeth.

vitamin c deficiency: hemorrhages

• Tiny hemorrhages (red spots) the size of appear in the skin, an indication that internal bleeding may also be occurring. Other symptoms include loss of appetite, growth cessation, weakness, frequent infections, bleeding gums, loose teeth, and swelling in wrists and ankles.

vitamin c toxicity

• vitamin c as a nutraceutical (marketing a nutrient as having pharmacological effects) have led thousand of people to take huge doses of vitamin c

• recommended 4,000mg per day

• one effect observed when 2 grams of vitamin c are consumed daily is altered insulin response to CHO in people with otherwise normal glucose tolerance

• other adverse effects include nausea, abdominal cramping, gas, diarrhea, and the development of kidney stones

• massive doses of vitamin c may also interfere with blood clotting medication and may be dangerous for individuals with iron overload (hemochromatosis) because of the role that vitamin c plays in enhancing iron absorption

the B vitamins

• thiamin

• riboflavin

• niacin

• folate

• vitamin B12

• vitamin B6

• biotin

• pantothenic acid

the B vitamins act as coenzymes

• coenzymes are small molecules that combine with enzymes to activate the enzyme

• without the coenzyme, the enzyme would be as useless as a car without wheels

the B vitamins are also involved in energy metabolism

• help body to metabolize CHO, fats, and amino acids

• they do not supply the body with energy directly, but rather hep the body to use the fuel from the energy providing nutrients

• thiamine, riboflavin, niacin, pantothenic acid, and biotin participate in the release of energy from CHO, fat, and protein

• vitamin B6 help the body use amino aids to make protein, while folate and vitamin B12 help cells to multiply, including the cells that deliver energy to all other cells

• therefore al of the B vitamin are directly or indirectly involved in energy metabolism

thiamin functions

• critical role in energy metabolism of all cels

• also occupies a site on nerve cell membranes

• therefore, nerve processes and muscles deepen heavily on thiamin

thiamin food sources

• small amounts of thiamin occur in many nutritious foods, such as legumes, enriched/whole grain cereals, sunflower seeds and pork

• by choosing nutrient dense foods, one can easily achieve their thiamin recommendation

thiamin deficiency

• is called beriberi

• characterization by loss of sensation in he hands and feet, muscular weakness, advancing paralysis and abnormal heart action

• can be wet (accompanied by edema) or dry (no edema)

• thumb print remains in the skin (wet beriberi) - a sign of edema

• serve thiamin deficiency called Vernickle-Korsakoff syndrome, in those who abuse alcohol

• not only does alcohol often displace foods for alcohol abusers, it also impairs the absorption of thiamin from the digestive tract, and speeds up its excretion in the urine

Verniicke-Korsakoff characterized

• apathy

• irritability

• mental confusion

• disorientation

• memory loss

• jerky eye movement

• staggering gait

beriberi first observed

• first observed in east asia where rice is a staple food

• polishing rice became popular, removing the brown outer coat, the thiamin

• swept through the population like an epidemic

• scientist is took a long time to realize it wasn’t a microorganism causing this but something lacking in the diet

riboflavin functions

• like thiamin, riboflavin plays a role in the energy metabolism of all cells. It also helps to support vision and skin health.

riboflavin food sources

• Enriched breads, cereals, pastas and other grain products contribute about 25% of our riboflavin intake, with the rest coming from milk products, eggs, meats and some vegetables (e.g., spinach, mushrooms).

riboflavin deficiency

• ariboflavinosis is the deficiency disease of riboflavin characterized by cracks and redness at the corners of the mouth (these cracks can actually start to spread down the sides of the face)

• smooth magenta coloured tongue, sore throat, inflamed eyes and eyelids, hypersensitivity to light, as well as skin rashes

• when diet is deficient in thiamin, it may be deficient in riboflavin (similar food sources)

• riboflavin deficiency often goes infected because the symptoms of thiamin deficiency are some severe

riboflavin toxicity

• there are no reported symptoms of toxicity

• no UL set at this time

• niacin functions

• participates in the energy metabolism of all cells

• tryptophan (an amino acid found in almost all proteins) can be converted to niacin in the body. therefore, person eating adequate amounts of protein will not be deficient in niacin

• niacin equivalents are the amounts of niacin present in food and take not account the niacin that can be created from the tryptophan present in food

niacin food sources

• enriched (added back to the natural level) & whole grains; cereals and baked products

• *legumes

• leafy green vegetables, mushrooms

• *meat, fish, eggs

• *milk & milk products

Almost all protein containing foods are a source of niacin and tryptophan. The only protein that is limited in tryptophan is the protein of corn.

niacin deficiency

• called pellagra

• symptoms include 4 D’s: diarrhea, dermatitis, dementia, and ultimately death

• also see headaches, abdominal pain, vomiting, and the tongue can become smooth, swollen and red or black in colour

• Pellagra appeared in Europe in the 1700’s when corn became a staple food (corn protein is limited in tryptophan). It is still common in parts of Africa and Asia.

niacin toxicity

• typically linked to supplements intake, rather than food intake

• niacin toxicity can cause ‘niacin flush’ - a dilation of capillaries of the skin with tingling sensation that can be painful

• hives also occur, as well as excessive sweating, blurred vision, liver damage, and impaired glucose tolerance

• other symptoms include: stomach pain, nausea, and diarrhea

• overtime the body adapts to high doses and many symptoms resolve, however it is important to monitor for liver damage, which can silently occur

niacin supplementation

• physicians may adminters a dose of niacin to lower blood lipid levels

• use as a drug

• self doses not advised

• rage doses cause damage to liver, peptic ulcers, and extreme conditions, vision loss

folate requirements

• folate supplement ion occurs before refinance occurs

• dri recommend pregnant women to consume 400 mg of folate a day form supplements or enriched foods addition to in natural foods

• form of folate is better absorbed in our body from supplements and enriched foods that naturally occurring (weird)

folate (folic acid) functions

• in order for new cells to be made, tissues must have folate

• each new cell must have copies f parents cell’s DNA and folate helps to synthesize this DNA

• cells that divide rapidly are most vulnerable to deficiency

• folate very important for early embryonic growth to prevent neural tube defects (abnormalities of the brain and spinal cord apparent at birth), as well as for tissues with fast turnover rates (e.d intestine, skin, RBC)

• critical for the normal metabolism of a number of amino acids

folate (folic acid) food sources

• deprived from latino word foliage, giving us an idea what foods are good sources

• leafy green vegetables, such as spinach and turnips greens are great source

• other vegetables such as broccoli and asparagus, fruit such as organs and organs juice, legumes, seeds, and liver also contain folate

• fresh uncooked vegetables and fruits are a good source of folate - heat and oxidation both destroy folate

• consuming milk with a mela may enhance folate absorption

• white flour, enriched pasta, and corn meal all have been fortified with folic acid in Canada. this was done as a public health strategy to increase dietary folate intakes and lower the incidence of neural tube defects, which we discuss further in this section.

• White flour is fortified with 0.15mg folic acid per 100g flour (about twice the amount found naturally in whole grain flour). Enriched pasta is fortified with 0.2mg per 100g. The amounts of folate added to foods was kept low because of concerns that higher levels may mask vitamin B12 deficiency (we will look at this with vitamin B12).

folate deficiency

• causes anemia (large cell-type), lowered immunity, and abnormal digestive function

• anemia is caused related to the anemia of vitamin B12, because both of these B vitamins work together to produce RBC

• large, immature RBC become present as a result

• other symptoms include smooth red tongue, depression, mental confusion, fatigue, irritability, and headaches

folate deficiency: neural tube effects

• also associated with neural tube defects (abnormalities of the brain and spinal cord apparent at birth)

• neural tubes occur the first days to weeks of pregnancy, before woman knows she’s pregnant

• neural tubes occur in 1/1,000 briths and are the second most common birth defect

• food surveys show us that most canadians do not eat enough vegetables and fruits each day to supply them with the needed folate, DRI recommends synthetic folate for all women of childbearing years

• between 2006 and 2020 1,832 cases of neural tube defects were reported in Canada

those at risk of folate deficiency include

• pregnant women

• elderly (many medications interact with folate absorption, e.g., antacids, aspirin, oral contraceptives, and anticonvulsant medications. The elderly may also may have lowered food intake)

• alcoholics (decreased folate absorption, also may have lowered food intake)

• smokers (folate inactivation in lungs occurs, increasing the need for folate)

Research suggests that a diet deficient in folate may increase the risk of cardiovascular disease, colon cancer and increase a woman’s risk of cervical cancer

folate toxicity

• The UL for synthetic folate is 1,000 ug /day for adults. The concern is that folate can mask Vitamin B12 deficiency by resolving the macrocytic anemia seen in both folate and B12 deficiency.

Vitamin B12 functions

• Vitamin B12 helps to maintain the myelin sheath that surround and protect nerve fibres.

• Without sufficient vitamin B12, nerves become damaged.

• It also acts as a coenzyme in energy and amino acid metabolism.

vitamin B12 food sources

• only present in foods of animal origin, not in foods from plants.

• However, many vegetarian foods are being fortified with vitamin B12 (soy beverages, soy meat alternatives)

• Algae are an exception of a plant food where we do find vitamin B12, and another vegetarian source of vitamin B12 is Red Star Yeast.

• Some fermented products contain this vitamin however it is typically not in its active form.

vitamin B12 deficiency

• Vitamin B12 and folate are closely related, each relies on the other for activation.

• Without sufficient vitamin B12, folate fails to do its red blood cell building work so vitamin B12 deficiency causes an identical anemia as folate deficiency does.

• Vitamin B12 deficiency can also cause neuromuscular dysfunction such as creeping paralysis and general malfunctioning of nerves and muscles.

• Administering folate often clears up the anemia, but allows the vitamin B12 deficiency (and corresponding neuromuscular dysfunction) to continue undetected.

vitamin B12 absorption

• requires intrusion tic factor, compound made in the stomach

• gastric acid liberates vitamin B12 from the food protein that binds it and the intrinsic factor attached to B12

• it is then absorbed into look stream in small intestine

• as we age, we do not produce enough gastric acids and instruct factor, not being able to absorbed enough vitamin B12

• some people have an inherited defect in the gene for intestine factor making absorption for vitamin B12 abnormal, this begins in mid adult hood

• if here is no intrinsic factor or reduce intrinsic factor, the individual typically needs vitamin B12 injections or high dose supplements

• a change in diet alone may not correct vitamin B12 deficiency

vitamin B6 (Pyridoxine) functions

• Vitamin B6 participates in over 100 reactions in body tissues and is needed to convert over abundant amino acids into other, non-essential amino acids the cells lack

other functions of vitamin B6 include

1. Energy metabolism

2. Synthesis of hemoglobin and neurotransmitters

3. Conversion of tryptophan to niacin

4. Releasing stored glucose from glycogen – thus contributes the regulation of normal blood glucose levels

5. Immune function and steroid hormone activity

6. Critical to the developing brain and nervous system in a fetus. Deficiency at this stage can cause behavioral problems later on.

Because vitamin B6 plays so many roles in protein metabolism, the requirements for vitamin B6 were created to be proportionate to protein recommendations

vitamin B6 food sources

• Meats, fish and poultry are good sources, along with potatoes, leafy green vegetables, and some fruits. Legumes and peanuts contain smaller amounts of vitamin B6

vitamin B6 deficiency

• cause weakness, psychological depression, confusion, irritability, insomnia, anemia (small-celled), and greasy dermatitis

• may also causes convulsions, and may weaken the immune system

• some evidence suggest that low vitamin B6 intakes may be related to an increased incidence of heart disease

vitamin B6 toxicity

• large doses from supplements can be dangerously

• reported symptoms in a women taking more than 2g for 2 months to relived PMS symptoms, she got numbness of hands and feet and couldn’t walked. this went away after she stopped the supplements

• other toxicity symptoms include: depression, fatigue, impaired memory, irrationality, headaches, restless, conflucsions

• only seen with supplements

• would need over 3,000 bananas or 38,000 chicken breast to get 2g a day - hard to go over limit on natural foods

• sometimes supplements are used to treat carpal tunnel, sleep disorders, or PMS syndromes

• research shows vitamin b6 supplements are ineffective to resolve any of those conditions

biotin function

• Biotin plays a role as a cofactor in energy metabolism