Week 3 Flashcards
Calcium, phosphorus, magnesium, sodium, potassium, chloride are all
Macrominerals
Macrominerals are required in amounts of
> 100 mg/day
Iron, zinc, copper, selenium, chromium, iodine, manganese, molybdenum, fluorine, nickel, silicon, vanadium, arsenic, born, cobalt are
Microminerals
Aka trace elements
Microminerals are required in amounts
<100 mg/day
Minerals constitute approx __% of total body weight
4%
T/F micronutrients require enzymes for absorption
False. Macronutrients (protein, fat, carb) do though.
Absorption of minerals takes place in the
Small intestine (duodenum, jejunum, ileum)
The absorption of minerals is affected by (3)
GI pH
Food components in the diet
Mineral-mineral interactions (evident in supplemental form)
Calcium absorption is enhanced by (2)
Lactose
Vitamin D
Calcium absorption is inhibited by (3)
Fiber
Phytate
Fatty acids
Iron absorption is enhanced by (2)
Vitamin C
Meat
Iron absorption is inhibited by (5)
Fiber Phytate Tannins (tea) Oxalate (spinach) Proteins (soy protein, egg protein, casein)
Zinc absorption is inhibited by
Fiber
Phytate
Tannins (tea)
Oxalate (spinach)
What mineral participants in the following functions: Nerve transmission Muscle contraction Synthesis of hormones and enzymes Mineralization of bones Blood clotting
Calcium
Insufficient serum calcium levels contribute to increased PTH and calcitriol, which
Demineralization bone tissue = osteoporosis
3 or ones regulate calcium
Parathyroid hormone
1,25(OH)2 vitamin D3
Calcitonin
Parathyroid hormone is produced in the
Parathyroid gland
1,25(OH)2 vitamin D3 AKA calcitriol is synthesized in the
Kidneys
Calcitonin is produced by
Thyroid gland
1,25(OH)2 vitamin D3 AKA
Calcitriol is the active form of vitamin D
Plasma calcium falls below 10mg/100 ml what happens?
PT gland secretes PTH
- PTH acts on kidney to form Calcitriol; Calcitriol stimulates kidney to conserve Ca
- PTH acts on bone to stimulate mobilization of Ca away from bone (and keep in plasma)
Calcitriol acts on intestine
1. Stimulates intestinal absorption of Ca
Calcitriol acts on bones
1. Mobilizes calcium away from bone
Plasma calcium rise above 10mg/100 ml what happens?
Thyroid gland secretes calcitonin, deposit Ca on bone tissue
Calcitriol deposits Ca on bone tissue
__ deficiency is most prevalent micronutrient def in the world
Iron
Followed by: vit A, iodine, zinc
2 forms of iron
Heme iron (animal foods) Non-heme iron (fortified and plant foods)
Storage form of Fe in body is called
Ferritin
What is the iron receptor name?
Transferrin receptor - the more tfR on a cell body, the more iron deficient
What plays a role in growth and immunity?
Zinc
Zn deficiency
Growth failure
Eczema, rashes, acrodermatitis enterohepatica
Susceptibility to infections
Complications during childbirth
___ is the storage form of Fe, ___ is the storage form of Zn
Ferritin; metallothionein
metallothionein is rich in what amino acid
Cysteine
What mineral participates in these reactions: collagen synthesis, melanin synthesis, cytochromes in respiratory chain, neurotransmitter synthesis
Copper (Cu)
What is Cu storage in tissues?
Ceruloplasmin
What genetic disorder involves Cu accumulating in tissues (excess)
Wilson’s disease
Wilson’s disease Sx
Psychiatric sx, liver disease
Genetic disorder that affects Cu levels in body, leading to Cu deficiency
Menkes disease
Menkes disease Sx
Sparse and coarse hair Growth failure Deterioration of the nervous system “Kinky hair disease” Results in death before age 3
Iodine forms 2 hormones that are synthesized by thyroid gland
T4, T3
90% of hormone released by thyroid gland is
T4
T3 and T4 are involved in the following processes (7)
Protein synthesis
Bone growth
Neuronal maturation
Cell differentiation
Regulation of protein, carb, fat metabolism
Regulation of vitamin metabolism
Increases electron transport chain activity
When serum T4 is low, pituitary gland secretes
TSH which enlarges thyroid gland
When serum T4 is normal or high,
TSH secretion stops
The pituitary gland is affected by what ?
Hypothalamus secretes TRH which enhances synthesis and release of TSH by the pituitary
Iodine deficiency is the most important cause of (2)
Brain damage Mental retardation (cretinism = irreversible form of mental retardation)
What mineral is incorporated into proteins?
Selenium
E.g. glutathione peroxidase, methionine R sulfoxide
Food sources of selenium
Meat
Seafood
Nuts
Dependent on soil content
Atoms or molecules with an imbalance of electrons are called
Free radicals
What can attack DNA, proteins, and PUFAs?
Free radicals
What protects from free radical attacks?
Antioxidants
Micronutrient antioxidants
Fe Selenium Vitamin C Zinc Copper and manganese Vitamin E Beta carotene Carotenoids
Why do mineral deficiencies occur? (5)
- Lack of consumption
- High consumption of foods that inhibit absorption (e.g. phytate, goitrogens)
- Poor consumption fo foods that enhance absorption (e.g. citrus fruits, lactose, vitamin D, low meat consumption)
- Disease, infection
- Stages of life (higher needs of minerals, increased mineral loss, decreased capacity to synth minerals)
Adding nutrients lost during food processing methods is called
E.g. adding B vitamins to cereal grains because during milling some B vitamins present in the bran are lost
Enrichment
Adding nutrients to foods that naturally do not contain those nutrients is called
E.g. adding vitamin A and D to milk; iodine to salt; iron to milk
Fortification
What is bio-fortification?
Fortifying crops with minerals
Breeding plants with increasing levels of components
Breed plants with decreased levels of inhibiting components
What mineral maintains fluid balance, nerve transmission/impulse conduction, muscle contraction?
Sodium
Deficiency = excessive sweating
Food sources of magnesium?
Coffee Tea Cocoa Nuts Legumes Whole grains
How to assess magnesium status?
Renal excretion before and after administration of Mg load
Food sources of potassium
Unprocessed foods
Some fruits and vegetables
Legumes, nuts, seeds
Kyperkalemia
High serum potassium
Can lead to cardiac arrhythmias and cardiac arrest
Hypo kale Mia
Low serum potassium
Can lead to muscular weakness, cardiac arrhythmias, hyper calcium is, mental disorientation
How to assess potassium
Plasma K concentrations
Food sources of phosphorus
Meat, poultry, fish
Eggs
Plants
Chloride food sources
Salt
Eggs
Fresh meat
Seafood
Chromium food sources
Meat, fish, poultry
Whole grains
Manganese interacts with (2)
Iron (inhibit each other)
Calcium (Ca decreases Mn absorption)
Food sources molybdenum
Legumes
Meat, fish, poultry
Grains
