vitamins and minerals pt 2 Flashcards
Vitamin C
• Vitamin C is a water soluble vitamin that primarily
functions as an antioxidant
– Donates an electron to free radicals to stabilize them and prevent them from destabilizing other important molecules
– Protects cellular membranes from being oxidized
– Protects LDL cholesterol from being oxidized
– Enhances immunity (protects white blood cells from oxidative
damage that takes place when fighting infection)
– Also acts as an antioxidant by regenerated oxidized vitamin E
• Also plays a role in regulating thyroid hormone
production
• Critical to the synthesis and maintenance of collage
why is weaving of connective tissue necessary
strong, healthy connective tissue
collagen must interveave or can tear apart
collagen is coenzyme for procollagen
bleed easily or have easy wounding
Vitamin C deficiencies rare in developed countries
____ is most common deficiency disease
AE
Scurvy
Adverse effects of Vitamin C are rare as excess is
excreted in the urine, very large doses of supplements
can cause
– Nausea
– Diarrhea
– Nosebleeds
– Abdominal cramps
– Harmful for people with hemochromatosis* (can’t transport iron, accumulate it and increases heart attack)
RDA for people 19 years or older
– 90 mg/day for men, 75 mg/day for women
– Smokers require 35 mg/day more
women with contraceptives need more of it
Vitamin A
retinal combines protein in rods and cones (opsin) to make rhadopsin, once light hits eye, retin dissociates with opsin and lets brain know therei s light
Vitamin A is a fat soluble vitamin that also functions as
an antioxidant and has 3 active forms
– Scavenges free radicals and protects LDL cholesterol from being
oxidized
– Essential for healthy vision
– Important for cell differentiation
– Reproduction (sperm production and fertilization)
– Bone growth
3 types of Vit A
retinol, retinal, retinoic acid
retional: vision, sexual reproduction, bone health, immune fxn
same for retinal
retinoic acid:L cell diff, bone health, immune function
retinal combines protein in rods and cones (opsin) to make rhadopsin, once light hits eye, retin dissociates with opsin and lets brain know therei s light
Vitamin A deficiency is associated with the following
why is it narrow window?
• RDA for people 19 years or older
– 900 μg/day for men, 700 μg/day for women
FYI
beef liver, beta cartoine can be converted to vit A
– Night blindness
– Hyperkeratosis
– Impaired immunity, failure of normal growth
Vitamin A is highly toxic and toxicity can be seen at doses 3-4x the RDA (mainly from supplements)
– Teratogenic (can cause spontaneous abortion)
– Fatigue
– Loss of appetite
– Hair loss & skin disorders
– Nausea & abdominal pain
The primary vitamins regulating bone health are
vitamins D and K
Vitamin D
role
• Vitamin D is a fat soluble vitamin that plays an
important role in bone health (also a hormone)
– Regulates blood Ca2+ levels (regulates calcium & phosphorous
absorption from the small intestine)
– Stimulates osteoclasts
– Can also contribute to bone calcification
7-dehdrocholesterol in melanocytes skin –> UV light convert it to cholecalciferol, conversion in liver to caclidiol –> kidneys convert to calcitriol
Vitamin D
which foods
• RDA for people 19 years or older
– 600 IU/day for both men and women
slide 45 not tested
• Most foods naturally contain little vitamin D
– Cod liver oil & fatty fish (e.g. salmon, mackerel)
– Fortified milk (100 IU/cup)
• Vitamin D deficiency is associated with the following
– Loss of bone mass
– **Rickets (children - bowed legs, knocked knees), osteomalacia (adults - fractures)
– Glucocorticoids can alter vitamin D metabolism
• Vitamin D adverse effects include (mainly from
supplements)
– **Hypercalcemia (can lead to bone loss)
Vitamin K
bone health
• Vitamin K is a fat soluble vitamin that plays an important role in both bone health and blood coagulation
– Required for production of osteocalcin
– Acts as a coenzyme for a number of proteins
(prothrombin) involved in blood clotting
• Plant form = Phylloquinone
• Animal form = Menaquinone
• Produced by our gut flora
- bone abs and remodelling by osteocalcin
- not shown that deficiency affects bones
- important in blood clotting
Vitamin K
main sources
inject vit K to newborns as they do not have the gut flora yet
• RDA for people 19 years or older
– 120 μg/day for men, 90 μg/day for women
• Food sources high in vitamin K include the following – Kale – Turnips – Brussel sprouts – Broccoli green leafy vegtables
• Vitamin K deficiency is associated with the following
– Excessive bleeding (impaired blood clotting)
• No known adverse effects from Vitamin K excess
Should you Drink Vitamin Water?
• Regular vitamin water has added sugars
• If you are eating a healthful diet that is adequate, moderate, balanced and varied
– You will be for most part consuming vitamins at the required RDA for maintaining healthy body function
minerals
- anything not talked about not in test
Minerals - required for body processes – regulate fluid and energy production – essential for bone and blood health – remove harmful metabolic byproducts – major (>100 mg/day) and trace (<100 mg/day)
Fluid Balance
Minerals important in regulating fluid balance include;
– Sodium 1.5g/day
– Potassium 4.7
– Chloride 2.3
– Phosphorous 700
Sodium role
Sodium is the major positively charged nelectrolyte in extracellular fluid
– Regulates fluid balance and blood pressure
– Assist in the initiation and transmission of nervous signals
– Nerve impulses in muscle are the impetus for muscle contraction
Sodium Toxicity & Deficiency
Hypertension (especially when combined with low potassium intake)
– Deficiency is rare but can lead to hyponatremia (intense physical activity, severe diarrhea)
hyponatremia, seizures, coma, death?
Potassium role
• Potassium is the major positively charged
electrolyte in intracellular fluid
– Also regulates fluid balance and the transmission of nerve impulses and muscle contraction
Potassium Toxicity & Deficiency
– Hyperkalemia (sinus bradycardia, cardiac arrest)
– Hypokalemia is rare (people taking diuretics that are not potassium sparing are at risk)
– A high Na+/low K+ is thought to be a major risk factor for hypertension
inject k into heart for cardiac arrest
Chloride role
• Chloride is a negatively charged electrolyte
obtained almost exclusively from table salt
– Together with sodium helps in regulating fluid balance
– Aids in digesting food as part of stomach acid
– Assists white blood cells in mediating immune responses
– Only toxicity from high chloride intake is hypertension
(due to high Na+ from table salt)
– Deficiency is rare (severe dehydration or vomiting)
Phosphorus role
major intracellular negatively charged electrolyte
– Most commonly found in the form of phosphate (PO4
3-)
– Works together with K+ to regulate fluid balance
– Plays a key role in bone formation
– Is important in the generation of energy from food (ATP)
Phosphorus Toxicity & Deficiency
– High blood phosphorus levels can cause muscle spasms and
convulsions (people taking excess vitamin D, kidney failure)
– Phosphorus deficiency is rare (oversecretion of parathyroid
hormone, vitamin D deficiency)
soft drinks (coke have 60 g of phosphoric acid, antimicrobial actions)
Antioxidant Minerals
– Selenium – Manganese – Copper – Iron – Zinc
Selenium
role
• Most of the selenium in our body is contained in
amino acids
– Storage form = selenomethionine
– Active form = selenocysteine
– Is a key component of glutathione peroxidase
– Also plays a role in the production of thyroid hormones
Selenium
toxicity
• Selenium Toxicity & Deficiency
– Supplementation can cause toxicity (brittle hair and nails,
skin rashes, GI upset, liver cirrhosis)
– Deficiency is rare but can cause Keshan (from province) disease = cardiomyopathy in absense of HTN or cv disease
– Deficiency can also lead to a form of cretinism (child has mental impairment
Manganese, Copper, Iron & Zinc
• Manganese, copper and zinc are part of the
superoxide dismutase antioxidant enzyme
system
• Iron is a component of catalase
Minerals Important in
Regulating Blood Health
Minerals important in maintaining healthy blood include – Iron – Zinc – Copper
Zinc
– plays a role in synthesizing the heme structure of
hemoglobin
• Copper
– is a key component of ceruloplasmin (key protein
involved in iron transport)
Iron
• Iron is a major component of oxygen-carrying proteins
in blood and muscle
– 2/3rds of our body’s iron is found in hemoglobin
– Iron is also a key component of myoglobin
– Iron is also a key component of cytochromes
• Iron storage and recycling
– Our bodies contain little iron (500-1500 mg in men & 300-1000 mg in women), and we reuse about 85% of iron released from hemoglobin breakdown
Iron absorption is affected by
– iron status
– stomach acid (frees up iron)
– amount of iron in the diet
– type of iron (heme iron in animals is more absorbable that nonheme iron in plants)
– other dietary factors present in food (e.g. polyphenols & phytates)
Iron toxicity and deficiency
– accidental iron overdose is the most common cause of poisoning
deaths in children <6 years of age in the USA
– iron supplements can cause GI upset
– iron must be avoided in people with hemochromatosis
– iron deficiency leads to anemia
Zinc role
• Plays an important role in many body systems
– Enzymatic functions
– Structural functions (3D structure of proteins)
– Regulatory functions
• Zinc deficiency
– Is rare but may be seen in individuals who consume
predominantly grain-based foods
Ø Phytates and fiber inhibit zinc absorption
– May cause delayed sexual maturation, impaired
appetite, and increased incidence of infections
Copper
• In addition to it’s role in the generation of
ceruloplasmin, copper also plays a role in the
synthesis of collagen and elastin
• Copper Deficiency
– Can lead to microcytic anemia
– Will cause symptoms similar to that seen with
hemochromatosis
• Copper Toxicity (Wilson’s disease)
– Can be treated with zinc supplements
Calcium
• Major function of calcium is to provide structure to our
bones
– 99% of calcium in our body is stored in the hydroxyapatite
crystals built up on the collagen foundation of bone
– blood calcium is very tightly controlled (PTH & vitamin D)
– plays a role in the normal transmission of nerve impulses
– Assists in muscle contraction
• Calcium toxicity and deficiency
– hypercalcemia (overproduction of PTH, cancer) can lead to fatigue, loss of appetite, constipation, and mental confusion
– hypocalcemia (vitamin D deficiency, disease impairing PTH production) can lead to muscle spasms and convulsions
Magnesium
• Major function of calcium is to provide structure to our
bones
– Total body magnesium content is about 25 grams, and 50 – 60% of
that is in our bones
– Influences the formation of hydroxyapatite crystals through its
regulation of calcium balance (vitamin D, parathyroid hormone)
– Key cofactor for over 300 enzymes (e.g. ATPases)
– Plays an important role in DNA and protein synthesis and repair
Magnesium toxicity and deficiency
– Pharmacological levels of magnesium cause diarrhea
– People with poor kidney function may be at risk for hypermagnesemia
– Deficiency can lead to muscle cramps, spasms, nausea, and weakness
– Long-term deficiency is associated with many chronic diseases (heart disease, hypertension, osteoporosis)
Fluoride
• Major function of fluoride is to promote mineralization and protect against cavities
– 99% of our body’s fluoride is stored in our teeth and bones as fluorohydroxyapatite (more resistant to destruction by acids and bacteria)
– AI ranges from 1-4 mg/day
• Fluoride toxicity and deficiency
– Difficult to be deficient for fluoride due to fluoridated water and dental products
– Excess fluoride intake can cause fluorosis (stained and pitted teeth, doesn’t show problems with teeth fxn)
– Fluoride deficiency leads to cavities
Iodine
• Iodine is required for the synthesis of thyroid hormones
– thyroid hormones are important for the regulation of body
temperature, basal metabolic rate, and growth
– iodine is found in high amounts in marine animals that
concentrate iodine from seawater (saltwater fish & shrimp)
– table salt often has added iodine (since 1924)
• Iodine toxicity and deficiency
– Deficiency leads to goiter
– Iodine deficiency during pregnancy
can cause cretinism*** (largest preventable brain condition)
sulfur, chromium
• Sulfur
– Helps stabilize 3-dimensional shape of proteins
– Assists with detoxification of of alcohol and various drugs in the
liver
– No DRI since we get sulfur from amino acids
• Chromium
– Enhances insulin’s ability to promote glucose uptake into cells
