vitamins + minerals

for exam three...

vitamin A functions

• integrity of epithelial cells

• bone growth

• cell membrane stability

• gene regulation

• vision

• maintenance of healthy cornea tissue

• immune function

vitamin A chemical forms

• retinol

  • most active form

  • stored in liver

• retinal

• retinoic acid

vitamin A food sources

• preformed (ready-to-use): animal-based + fortified foods

  • fortified milk, cheese, cream, butter, eggs, liver

  • bioavailability: 70-90%

• provitamin (converted to active form as needed): plant-based foods

  • green leafy veggies, orange + red produce

    • apricots, cantaloupe, carrots, sweet potatoes, pumpkins

  • example: beta-carotene

  • bioavailability: variable 9-22%

vitamin A deficiency + toxicity

• short-term deficiency:

  • night blindness

  • dry, damaged cornea

• long-term deficiency:

  • xerophthalmia

  • permanent vision loss

• toxicity:

  • liver damage

  • birth defect

  • malformations of the head/face, heart, brain, + spinal cord

  • iron deficiency

vitamin D functions

• aka cholecalciferol

  • classified as vitamin, hormone, + steroid! :0

• regulation of calcium metabolism

  • stimulates cells of small intestine to produce calbindin

    • calcium-binding protein

    • can increase calcium absorption

  • stimulates kidneys to conserve calcium

    • decrease urinary calcium excretion

  • stimulates calcium release from bone to help maintain blood calcium levels

vitamin D food sources

• recommended intake increases with age

  • decreased ability to convert vitamin into its active light

  • decreased likelihood of adequate exposure to sunlight

• very few foods naturally concentrated

  • cod liver oil, sardines, salmon, shrimp, liver, mushrooms exposed to UV light

• fortified foods

  • strictly regulated!

  • milk/margarine, cereals, juices

  • cheese + yogurt not often fortified

• can make our own!

  • cholesterol in skin + UV rays → precursor of vitamin → kidneys → converted to active form (3)

  • factors that influence synthesis:

    • distance from equator

    • amt of clothing covering body

    • sunscreen use

    • cloud cover/smog

    • skin color

    • age

vitamin D deficiency + toxicity

• deficiency:

  • high rates in the US!

  • children:

    • rickets

      • softening + deformity of long bone

      • inability to deposit calcium in newly formed bone

    • malformation of skull, rib cage, + ends of long bones

  • adults:

    • osteomalacia: softening of bone caused by decalcification

  • links with chronic disease

    • heart disease, respiratory infections, diabetes, hypertension

• toxicity: uncommon!

  • overuse of supplements

  • nausea

  • vomiting

  • diarrhea

  • calcification of soft tissues

vitamin E functions

• primarily found in cell membrane

• many compounds (tocopherols): alpha, beta, gamma, delta

• antioxidant

  • neutralize free radicals by donating an electron

    • unstable compounds with an unpaired electron

    • attack other molecules with electrons

    • initiates chain reaction

    • damages cell membranes, proteins, enzymes, DNA

• enhances immune function

• required for nerve cell development

vitamin E food sources

• in past, supplements recommended to protect against cancer + cardiovascular disease

• some plant oils

• peanuts

• red bell pepper

• pumpkin

• avocado

vitamin E deficiency + toxicity

• deficiency: rare!

  • most likely in premature infants + insufficient stores

  • anemia

    • red blood cell fragility + subsequent rupture

  • loss of muscle coordination + reflexes

  • muscle weakness

  • reproductive failure

  • impaired vision

• toxicity:

  • headache

  • nausea

  • blurred vision

  • reduced sexual function in men

  • accelerated signs of aging

  • inflammation of mouth

  • chapped lips

  • fatigue

  • GI disturbances

  • muscle weakness

  • increased bleeding

vitamin K functions

• blood clotting

• activates proteins required to make fibrin

  • forms blood clots

• synthesis of osteocalcin

  • "bone protein”

  • produced by osteoblasts

vitamin K food sources

• produced by microbiome in large intestines

  • most significant source for humans

• green vegetables

  • spinach, kale, + cruciferous vegetables

• green fruits

  • avocado + kiwi

• some vegetable oils

vitamin K deficiency

• rare in adults!

• populations @ risk for deficiency:

  • newborns at highest risk!

    • relatively sterile GI tract @ birth

    • breast milk poor source of vitamin

    • single dose of vitamin given @ birth

  • prolonged antibiotic use

vitamin C functions

• aka ascorbic acid

• antioxidant

  • immune system health

• collagen synthesis

  • protein that forms connective tissues of tendons, bone, teeth, + skin

  • wound healing

  • maintenance of blood vessel structure

• facilitates iron absorption in GI

vitamin C food sources

• fruits and vegetables

  • orange juice

  • citrus fruits

    • limes + lemons

  • bell pepper

  • kiwis

  • strawberries

  • sweet potatoes

  • brussels sprouts

• vulnerable to heat + oxygen!

  • food prep affects vitamin levels in food

vitamin C deficiency

• scurvy

  • sailors of the 1800s :P

  • bleeding gums

  • tooth loss

  • poor wound healing

  • small hemorrhages on skin

  • improper formation of collagen

• anemia

  • poor iron absorption

• weakness

• impaired growth

• scorbutic rosary in infants

B vitamins

• functions: coenzymes or cofactors in energy metabolism

  • assist enzymes with energy release

    • without coenzyme, enzyme cannot function :(

• vitamins:

  • thiamin (1)

  • riboflavin (2)

  • niacin (3)

  • pyridoxine (6)

  • folate (9)

  • 12

vitamin B1 functions

• aka thiamin

• part of coenzyme thamin pyrophosphate (TPP)

  • assists in metabolism of carbohydrates + some amino acids

  • conversion of pyruvate to acetyl coA

  • kreb’s cycle

• assists in function of nerve + muscle cell activity

vitamin B1 food sources

• pork

• whole grains

• fortified breakfast cereals

• enriched grains

• peanuts

vitamin B1 deficiency

• malnourished individuals: beriberi

  • condition where heart becomes enlarged

    • fluid accumulates beneath skin

    • muscles weaken + atrophy

  • if condition primarily affects cardiovascular system: wet beriberi

  • if condition primarily affects nervous system: dry beriberi

• alcoholics: wernicke-korsakoff syndrome

vitamin B2 functions

• aka riboflavin

• part of coenzymes

  • flavin mononucleotide (FMN)

  • flavin adenine dinucleotide (FAD)

• energy release from macronutrients

  • FAD “electron shuttle”

vitamin B2 food sources

• eggs

• milk

• enriched breads, cereals, + pasta

• vitamin destroyed by UV light + irradiation

vitamin B2 deficiency

• frequently in conjunction with other water-soluble vitamin deficiencies

• inflammation of membranes

• sore throat

• cracks in corners of mouth

• swollen, glossy tongue

• skin rashes

• hypersensitivity to light

vitamin B3 functions

• aka niacin

• release energy from macronutrients

  • almost any metabolic pathway uses resulting coenzymes!

    • nicotinamide adenine dinucleotide (NAD)

    • nicotinamide adenine dinucleotide phosphate (NADP)

• synthesis of fatty acids

vitamin B3 chemical forms

• nicotinamide

• nicotinic acid

vitamin B3 food sources

• milk

• eggs

• meat

• poultry

• fish

• whole grain + enriched breads + cereals

vitamin B3 deficiency + toxicity

• deficiency: pellagra

  • “four Ds”: diarrhea, dermatitis, dementia, death

  • big issue in early 1900s-1930s

    • diet void of niacin

      • fat back, grits, molasses

• toxicity: one of the few water-soluble vitamins to have toxicity symptoms

  • overconsumption of supplements or fortified foods

  • “flush”: temporary condition

    • consumption of 3-4x RDA

    • common cause: high doses of nicotinic acid prescribed for cholesterol reduction

    • redness of face, arms, + legs

    • liver injury

    • tingling sensation

vitamin B6 functions

• aka pyridoxine

• participation in diverse biochemical reactions

• transamination

  • synthesis of nonessential amino acids

• synthesis of

  • glucose

  • some types of lipids

  • hemoglobin

• production of serotonin

vitamin B6 food sources

• beef liver

• meat

• poultry

• salmon

• baked potatoes

• bananas

• watermelon

• navy + pinto beans

vitamin B6 deficiency + toxicity

• deficiency: occurs with deficiency of other B vitamins

  • anemia

  • depression

  • dermatitis

  • convulsions

  • weakened immune response

• toxicity: many symptoms not reversible :0

  • alterations of nerve function

    • numb feet

    • loss of sensation in the hands

    • damage → inability to walk

vitamin B9 functions

• aka folate

• required for DNA replication during cell division

• red blood cell synthesis

• central nervous system formation during fetal development

vitamin B9 food sources

• folate: naturally-occurring

  • orange juice

  • green, leafy vegetables

  • legumes

  • seeds

  • egg yolk

• folic acid: synthetic form, easier to absorb in GI

  • supplements

  • enriched grains

• increased consumption for:

  • women planning on becoming pregnant

  • pregnant + lactating women

vitamin B9 deficiency

• inability to synthesize DNA

• macrocytic anemia

  • large, immature red blood cells fewer in number

• during pregnancy: neural tube defects

  • spina bifida: failure of spinal cord to close completely

  • anencephaly: lack of or incomplete development of brain + skull

vitamin B12 functions

• contains cobalt as part of its structure

  • mineral!

• conversion of folate into active form

• maintains myelin sheath

  • insulating lining that covers nerve fibers

• + folate: homocysteine metabolism

  • high levels of homocysteine in blood = increased risk of cardiovascular disease

vitamin B12 food sources

• animal-based foods:

  • milk, cheese, meat, poultry, seafood

    • especially organ meats!

• fortified foods with vitamin B12

  • ready-to-eat cereals

  • soy products

  • supplements

    • recommended for adults > 50 years

• absorption:

  • must be released from dietary protein before it can be absorbed

    • occurs in stomach

    • HCl + pepsin

  • after release, bound by intrinsic factor

    • glycoprotein secreted in stomach

    • protects vitamin from degradation until absorption in lower ileum

  • decreases during aging

    • decreased intrinsic factor

    • decreased HCl secretion

    • decreased ability to release vitamin from dietary protein

vitamin B12 deficiency

• macrocytic anemia

• pernicious anemia:

  • if due to lack of intrinsic factor

  • can occur in:

    • genetic defect

    • aging

    • portion of stomach removed

      • roux-en-Y surgery (bariatric surgery)

      • stomach cancer

calcium functions

• most abundant mineral in body

• constantly deposited into + released from bone

• hormone regulation

  • a hormone’s impact on a cell may be mediated by the hormone’s effect on cellular mineral levels

    • hormone binds to cell surface receptor

    • triggers release of mineral in cell

• building + maintenance of bone

  • mineral in bone, along with phosphorous

  • makes up hydroxyapatite

    • provides bone strength

    • in addition to magnesium, sodium, phosphorous, + fluoride

  • constant state of remodeling + turnover

    • simultaneous breakdown + rebuilding

    • enables adaptation to physical stress, injury, growth, + nutritional changes

    • density peaks around mid thirties

• muscle contraction

  • enters muscle cells to initiate contraction

• conduction of nerve impulses

  • release of neurotransmitters

  • regulation of levels of Na+ + K+ ions across nerve membrane

• blood clotting

  • prothrombin → thrombin

• protection from hypertension

  • pre-eclampsia

  • eclampsia

calcium food sources

• dairy products

• canned sardines

• salmon with bones

• turnip greens

• broccoli

• green, leafy vegetables

  • exception: spinach

• supplements + functional foods

• blood levels tightly regulated by vitamin D + parathyroid hormone

  • response to low levels: intestine, bones, + kidneys

• dietary factors that can decrease absorption:

  • phytates

  • oxalate

• dietary factors that can increase absorption: lactose

calcium deficiency

• osteoporosis: bones become porous (loss of strength + density)

  • higher risk of fractures + breaks

  • common bone disease in western countries

  • most prevalent in people > 50 years, but may occur as early as 20 years

  • no cure :(

  • prevention:

    • balanced diet with adequate intake of __ + vitamin D

    • regular exercise

      • aerobic

      • strength

    • avoid smoking

    • limit alcohol intake

  • risk factors:

    • non-modifiable:

      • female

      • older age

      • small frame

      • caucasian or asian

      • family + personal history

      • estrogen deficiency in women

        • amennorhea or menopause

    • modifiable:

      • sedentary lifestyle

      • diet

      • smoking

      • excess alcohol consumption

      • low body weight

      • use of certain medications

• osteopenia/malacia: weakening/.softening of bone density

  • bone loss > bone gain or maintenance

magnesium functions

• component of hydroxyapatite crystals in bone matrix

  • bone = storage

• with phosphorus: maintenance of DNA + RNA integrity

• facilitates muscle relaxation

• cofactor for many different enzymes

magnesium food sources

• green, leafy veggies

  • spinach, collards, turnip greens

• unpolished grains

• legumes

• nuts

• whole-grain cereals + breads

• chocolate

• absorption may decrease with low protein intake

phosphorous function

• second most abundant mineral in body

• usually found as a phosphate

  • part of ATP!

    • “usable” form of energy

    • most B vitamins become active when attached

• part of bones + teeth

• facilitates enzyme function (+ vice versa)

• component of:

  • DNA

  • RNA

  • phospholipid

    • cell membranes + lipoproteins

• acid-base buffer

phosphorus food sources

• meat

• fish

• poultry

• eggs

• milk + milk products

• cereals/grains

• legumes

• tea

• coffee

• chocolate

• soft drinks

sulfur functions

• in the past: used in potions

• primarily stored in:

  • methionine

  • cysteine

    • can bond to another cysteine to form a bridge or link

• key element in glutathione

  • strong antioxidant in body

sulfur food sources

• protein-containing foods

• plant-based foods: depends on soil’s content

  • FDA banned use of additives in fresh fruits + veggies

• added in foods for preservation or flavoring (can cause sensitivity)

  • breads + other baked goods

  • dried foods

  • canned or pickled foods

  • condiments

  • wine + beer

iron functions

• assistance in delivery of oxygen to tissues + cells (!!!)

  • found @ center of hemoglobin molecule

  • delivers oxygen to tissues + cells in body → picks up carbon dioxide

• stored in relatively small amounts

iron food sources

• heme: form found in hemoglobin

  • meats, fish, + poultry

  • more readily absorbed in body

• non-heme: elemental form

  • plant-based + enriched foods

  • less readily absorbed in body

  • factors that enhance absorption: vitamin C, MFP

  • factors that reduce iron absorption: tannins/polyphenols, phytates, calcium

iron deficiency + toxicity

• deficiency: anemia

  • clinical condition in which hemoglobin level is too low

  • possible causes:

    • low-mineral stores

    • inability to use mineral for hemoglobin synthesis

    • inadequate intake

    • inadequate absorption

    • copper deficiency

    • blood loss

• toxicity:

  • hemochromatosis: genetic disorder that can cause toxicity

    • inability to regulate amount of mineral absorbed

  • abdominal pain

  • fatigue

  • depression

  • advances to liver damage

zinc functions

• development of sexual organs + bone growth

• alcohol metabolism

• antioxidant enzyme function

• blood pressure regulation

• insulin release + function

• DNA replication

• protein synthesis, growth, + development

• immune function

• hemoglobin synthesis

zinc food sources

• meats

• poultry

  • specifically turkey!

• oysters

• herring

• eggs

• legumes + whole-grain cereals

  • decreased absorption due to presence of phytates

zinc deficiency

• limited growth in young teens, particularly males

• poor sexual development

• deformed bones

• abnormal hair + nails (loss of hair)

• poor wound healing

• hypogeusia

• GI disturbances

• impaired folate + vitamin A absorption

copper functions

• cofactor for enzymes

• needed for absorption, storage, + metabolism of iron

• antioxidant defense against free radicals

• strengthening collagen

• immune defense

• synthesis of neurotransmitters

• energy production via ATP synthesis

copper food sources

• organ meats

  • liver!

• shellfish

• chocolate

• nuts

• legumes

• drinking water

iodine functions

• facilitates production of thyroxine in thyroid gland

  • controls BMR

iodine food sources

• seafood

• iodized salt

• plants grown in areas with sufficient mineral in soil

iodine deficiency + toxicity

• deficiency: enlarged thyroid gland cells

• toxicity: enlarged thyroid gland cells

water-soluble vitamins

• short-term storage in body

• small quantities

• decreased likelihood of toxicity

• greater risk of deficiency

• examples:

  • vitamin C

  • all B vitamins

fat-soluble vitamins

• long-term storage in body

• large quantities

  • in liver + fat cells

• increased likelihood of toxicity

• lessened risk of deficiency

• examples:

  • vitamin A

  • vitamin D

  • vitamin E

  • vitamin K