Vitamins and Minerals Flashcards
The most widely used method of assessing vitamin B6 status is by the activation of ______________ by pyridoxal phosphate added in vitro, expressed as the ________________.
erythrocyte transaminases
activation coefficient
In Excess, Vitamin B6 Causes:
Sensory Neuropathy
There is some slight evidence that taking 2 to 7 g of pyridoxine per day is effective in treating:
premenstrual syndrome
VITAMIN ____ IS FOUND ONLY IN FOODS OF ANIMAL ORIGIN
B12
Deficiency state that results from inadequate absorption
Secondary
Deficiency state that results from increased requirement
Secondary
Deficiency state that results from inadequate intake
Primary
Deficiency state that results from medication
Secondary
The nine B vitamins are considered as:
water soluble or fat soluble?
water soluble
(B1, B2, B3, B5, B6, B7, B9, B12)
also Non-B complex (ascorbic acid/ vitamin C)
Which classification of vitamins are mostly converted to co-enzymes and are used in metabolic pathways and hematopoiesis?
Water-soluble
Fat soluble vitamins are only absorbed with:
fatty acids, bile, and pancreatic secretions
Which classification of vitamins can be stored in the liver and adipose tissue?
Fat soluble
Which fat soluble vitamin has a coenzyme function?
Vitamin K
Which classification of vitamins is more likely to cause toxicity with overdose or megadose?
Fat-soluble
Which classification of vitamins is needed in frequent doses?
Water-soluble
Which classification of vitamins is needed in periodic doses (weeks to months)?
Fat-soluble
True or False:
Minerals regulate enzyme activity
true
True or False:
Minerals maintain acid balance and osmotic pressure
True
Which of the following is not characterized by minerals?
A. Facilitates membrane transfer of essential compounds
B. Helps in maintaining nerve and muscular activity or irritability
C. May be structural constituents to body tissue
D. Involved directly in the growth process
E. Regulates enzyme activity
D. involved INDIRECTLY in the growth process
Macrominerals are essential at levels ____ mg/day for adults
100 mg/day
Required intake of Trace elements is less than ____ mg/day
1000
Which of the following is a macromineral? A. Magnesium B. Manganese C. Chylomicron D. Copper
A. Magnesium
→ Macrominerals are calcium, phosphorus, magnesium, sulfur, sodium, potassium, chloride
Which of the following trace elements has no clear function? A. Cobalt B. Molybdenum C. Silicon D. Selenium
C. Silicon
Essential trace elements, function not clear
▪ Silicon, vanadium, nickel, tin, cadmium
Which macrominerals are important for tissue/bone structure?
Calcium
Magnesium
Sulfur
Which macrominerals are important for membrane function and have regulatory roles?
Sodium
Potassium
Chloride
Which trace element, though essential but with no clear function, is quite toxic in excess?
Cadmium
Main active form of Vitamin A
retinol (all-trans-retinol)
What are the other active forms of Vit A apart from retinol?
▪ Retinaldehyde (instead of OH group, has an aldehyde)
▪ Retinoic acid (all-trans retinoic acid; carboxyl group)
▪ Beta-carotene
Precursor of vitamin A
carotenoids or carotenes
The most important precursor of Vit A
beta-carotene
Which vitamin is formed from cryptoxanthines?
Vit A
Beta-carotene (carotenoids) is cleaved in the intestinal mucosa by ______ forming retinaldehyde or retinoic acid
carotene dioxygenase
lipoprotein that carries retinol to the liver
Chylomicron
Beta-ionone ring is found in which vitamin?
Vitamin A
True or False:
Conversion of carotenoids to retinol is nearly 100%
True
Which fat-soluble vitamin is important for the synthesis of transferrin?
Vit A
Which fat-soluble vitamin functions for Growth and maintenance of epithelial tissues?
Vit A (Retinol and retinoic acid)
Amino acid residue of opsin for combination with 11-cis retinal?
Lys
Which vitamin A receptor binds both all-trans-retinoic acid and 9-cis-retinoic acid?
retinoic acid receptor (RAR)
Which vitamin A receptor binds only 9-cis-retinoic acid?
retinoid X receptor (RXR)
__________ is a chain-breaking antioxidant that acts on radicals derived from PUFAs (Polyunsaturated fatty acids) in lipid peroxidation
β-carotene
True or False:
Vitamin A has a role in the differentiation of immune cells.
True
Foods that normally have pre-formed retinol
→ Liver, egg yolk, milk, butter
Main sources of carotenoids:
→ mainly from plant sources – dark green and yellow vegetables, tomatoes, sweet potatoes, oily fruits, and red palm oil
Vitamin deficiency of patient with abnormal dryness of the conjunctiva and cornea of the eye with inflammation with ridge formation (leading to total blindness)
Vit A (xerophthalmia = keratinization of cornea)
Vitamin A deficiency can be biochemically equivalent to which type of anemia?
Iron-deficiency anemia
but in the presence of adequate iron intake
Deficiency of which form of vitamin A can repress gene expression?
9-cis retinoic acid
Added micrograms retinol equivalent for lactating mothers
400
Added micrograms retinol equivalent for pregnant women
300
Patient presented with inflamed lips, bone pain (possible hip fracture or calcification), scaly dermatitis, enlargement of liver and spleen, nausea, and diarrhea. What vitamin state should be assessed?
Excess Vitamin A or Hypervitaminosis A
Initial sign of Hypervitaminosis A
Cheilitis (inflammation of lips) or dry lips
True or False:
Free vitamin A in circulation doesn’t usually cause membrane lysis and tissue damage
False:
Unbound vitamin A can cause membrane lysis and tissue damage
Headache, nausea, ataxia, anorexia is expected in hypervitaminosis A due to:
Increased cerebrospinal fluid pressure
Precursors of Vitamin D
→ 7-dehydrocholesterol (animals)
→ ergosterol (plants)
Active form of Vit D
1, 25 dihydroxycholecalciferol
also called calcitriol
How is calcidiol formed
Hydroxylation of cholecalciferol (Vit D3) in the liver
Calcidiol is aka 25-OHD or 25-hydroxycholechalciferol
Hydroxylation at which carbon yields an inactive dihydroxyvitamin D
24
Which form of vitamin D is present in the circulation and is used to measure in the laboratory for Vit D assay?
Calcidiol or 25-OHC or 25-hydroxycholcalciferol
Overall effect of calcitriol in the body in terms of macrominerals is:
increased plasma calcium and phosphate
Calcitriol is involved in the following processes EXCEPT
A. Modulation of cell proliferation
B. Increase production of interleukins
C. Insulin secretion
D. Synthesis and secretion of parathyroid and thyroid hormones
E. T-lymphocyte and immunoglobulin production by B-cells
B. should be → inhibition of production of interleukins
Vitamin D potency:
1 mcg cholecalciferol or ergocalciferol is equal to ___ IU
40 IU
True or False:
RDA for Vit D increases with age
True • Infants (months, μg) → 0-11: 5 (♂, ♀) • Children (years, μg) → 1-18: 5 (♂, ♀) • Adults (years, μg) → 19 – 49: 5 (♂, ♀) → 50-59: 10 (♂, ♀) → 60 ->70: 15 (♂, ♀)
True or False:
There is NO added requirements for Vit D for pregnant and lactating mothers
True
How are foods fortified with ergosterol (D2)?
irradiating ergosterol from yeast
e.g., milk and butter
What form of Vit D is absorbed from plants such as mushrooms?
ergocalciferol
True or Fals:
One food source of Vit D is freshwater fish
False:
Should be
• Saltwater fish (salmon, sardines, and herring), liver and egg yolk
The most common symptoms of vitamin D deficiency in young children
Rickets
The most common symptoms of vitamin D deficiency in adults
osteomalacia