Vitamin B6/B9/B12 Flashcards
Vitamin B9 is also known as?
Folate
How many forms of B9 are there operating in the body?
150 forms
What is the most active coenzyme form of B9:
(THF) Tetrahydrofolate
Vitamin B9 (Folic Acid) is active in most (fortified) foods as what coenzyme form?
Polyglutamate
What food sources are most associated with vitamin B9 (folate)?
Green Vegetables
What are some common sources of vitamin B9 (folate)?
Green Vegetables
Citrus Fruits (esp. strawberries & oranges)
Yeast
Mushrooms
Legumes
Liver
Fortified Foods
Vitamin B9 (folate) is easily destroyed due to?
Processing (b/c of structure)
In order for folate to be present as polyglutamate, it must be hydrolyzed by what prior to absorption?
Conjugase
The enzyme conjugase is inhibited by?
low zinc status, alcohol, and food inhibitors
Vitamin B9 (folate) functions in single carbon transfers in what to physiological processes?
Nucleic Acid Synthesis & Amino Acid Metabolism
Folate is a carbon donor in _____ synthesis?
Purine Synthesis
Folate is essential for _______ division?
Cell Division
In amino acid metabolism, _______ is converted to methionine glycine, and then converted to serine.
Homosysteine
Homocysteine is associated with what disease state?
CV disease
__________ Anemia is associated with Folate deficiency?
Megaloblastic Anemia (big RBC’s)
Megaloblastic Anemia occurs due to decreased ______ synthesis and _______ cell division along with continued RNA production.
Decreased DNA Synthesis
Improper Cell Division
Symptoms of Megaloblastic Anemia (or all types of anemia’s) would include?
Pale
Fatigue
Concentrating
Headache
Dyspnea
In pregnancy, birth defects are highly correlated with ________ deficiency?
Folate
Populations at risk for folate deficiency include?
Pregnancy
Elderly
Alcoholism
Phenytoin User (anticonvulsant)
Supplementation of folate can mask vitamin _____ deficiency, but still allow for neurological damage to occur from being deficient.
B12
Megadoses of folate can induce _______ in what population?
Seizures in epileptics
What is the upper limit of Folate?
1 mg/day from supplements & fortified foods.
Why is vitamin B12 imperative for Vitamin B9 (folate) interactions?
Methyl-Folate Trap: B12’s is needed to remove methyl group from N5 methyl THF.
Folate may decrease _____ absorption?
Zinc
_______ deficiency may decrease folate absorption?
Zinc
What is a general assessment for Vitamin B9 (folate)?
Plasma, Serum, or RBC folate levels
What is are specific assessments for Vitamin B9 (folate)?
Deoxyuridine Suppression Test
Plasma Homocysteine Concentrations
Vitamin B12 is also known as?
Cobalamin “Cobalt”
Vitamin B12 (Cobalt) is found primarily in what food sources?
Animal Products are the main sources
Vitamin B12 (cobalt) is made by ________ in the digestive tract of animals.
Microbes
Vitamin B12 (cobalt)’s primary absorption is mediated by?
Intrinsic Factor
(IF = glycoprotein synthesized @ stomach)
When traveling from the stomach to the small intestine, vitamin B12 (cobalt) must combine with ______ to complete this transport process.
R Protein
When far enough through the digestive tract (but before the Ileum), Vitamin B12 releases it’s transport R Protein to combine with what?
Intrinsic Factor
Vitamin B12 + IF is absorbed where in the digestive tract?
Ileum
Vitamin B12 + IF is absorbed where in the digestive tract?
Ileum
Vitamin B12 is released from IF once the complex reaches where in the digestive tract?
Enterocyte
What is the secondary method for vitamin B12 absorption?
Diffusion
(primarily utilized in large doses: B12 shots)
Vitamin B12 (cobalt) functions to convert homocysteine to _______, through the transfer of a _______ group.
Homocysteine > (methyl group) > Methionine
Vitamin B12 (cobalt) functions in KREBS by by converting methylmalonyl CoA into?
Succinyl CoA
Vitamin B12 (cobalt) additionally functions in ________, possibly through the reduction of ribonucleotides to deoxyribonucelotides.
Nucleic Acid Synthesis
Vitamin B12 (cobalt) additionally functions in ________, possibly through the reduction of ribonucleotides to deoxyribonucelotides.
Nucleic Acid Synthesis
Vitamin B12 deficiency is commonly associated with?
Megaloblastic Anemia
What are some symptoms commonly associated with megaloblastic anemia?
Large immature RBC’s, neuropathy, increased MCV (mean corpuscular volume)
Vitamin B12 (cobalt) deficiency is most commonly associated with _______ conditions in populations, resulting in decreased IF production rather than dietary deficiency.
Genetic Conditions
Populations at risk for vitamin B12 (cobalt) deficiency are?
Elderly,
Disease/Surgery to Ileum,
Alcoholics,
Vegans
Stomach Surgery Recipients
What is are some assessments for Vitamin B12 (cobalt) deficiency?
Serum B12 (“schilling test”) or Plasma Homocysteine
What does the schilling assessment look/test for?
Tests B12 Absorption
& Presence of IF
Vitamin B6 is also known as?
Pyridoxine
Vitamin B6 (Pyridoxine) has coenzyme forms?
PL
PM
PN
PLP
PMP
PNP
Vitamin B6 (Pyridoxine) is stable when _______, but can be negatively affected in _______?
Stable when cooking
Long-Term Storage can effect B6
What are some food sources of Vitamin B6 (Pyridoxine)
Liver,
Nuts,
Bananas,
Legumes,
Meat,
Whole Grains,
Salmon,
Sirloin Steak,
White Meat Chicken
Where does all Vitamin B6 (Pyridoxine) metabolism occur?
Liver
Vitamin B6 (Pyridoxine) functions most importantly in _______ metabolism?
Amino Acid Metabolism
Functions of Amino Acid Metabolism that Vitamin B6 (Pyridoxine) is responsible for include?
Transamination
Decarboxylation
Transulfhydration
Desulfhydration
Clevage
Vitamin B6 (Pyridoxine) is also important in the function of _______ formation, and ______ synthesis.
Heme Formation
Niacin Synthesis
Vitamin B6 (Pyridoxine) functions in energy synthesis through _______ & _______?
Lineoleate (Fatty Acid Synthesis)
Glycogenolysis (Glycogen Phosphorylase)
Low levels of Vitamin B6 (Pyridoxine) have been associated with which diseases & conditions?
Coronary Heart Disease
Premenstrual Syndrome (PMS)
Carpal Tunnel Syndrome
Symptoms of Vitamin B6 (Pyridoxine) can be showcased as?
Lethargy in Adult
Seizures in Infants
Hypochromic
Microcytic Anemia
Depression
What are some populations at risk for Vitamin B6 (Pyridoxine) deficiency?
Breastfed Infants of Mothers w/ Deficiency
Elderly
Alcoholics
Oral Contraceptive Users
Vitamin B6 (Pyridoxine) toxicity limits are?
Upper Limit: 100 mg/day
Patients with neuropathy are advised to not exceed an RDA of ______ for vitamin B6 (Pyridoxine)
13 mg/day
What are assessments for vitamin B6 (Pyridoxine)?
Plasma PLP
Transaminase Activities
Tryptophan Load