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Micronutrients > B6 > Flashcards

Flashcards in B6 Deck (13)
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1

Interaction with tryptophan

Increases serotonin
Antidepressant

2

Comes in 3 forms

Pyridoxine PN (most stable form, found in plants and supplements). Alcohol form.

Pyridoxal PL. Aldehyde form. Animal.
Pyridoxamine PM. Amine form. Animal.

All have 5' phosphate derivative

3

Schiff base

Binds to AA to make Schiff base.
Active phosphorylated form.

Coenzyme functions.

4

PLP

Liver main site of synthesis. RBC. 10% stored in liver. 80% stored in cell.

PLP food source hydrolyzed by zinc dependent phosphatase prior to uptake. Creates PL.

PL rephosphorylated in cell.

5

PLP Storage

In blood: PLP bound to albumin (protect from phosphatase)

Unphosphorylated passively diffuse.

80% stored in muscle bound to glycogen

In RBC: PLP bound to hemoglobin

6

Interactions with other nutrients

Riboflavin maintains B6

Works with thiamin in Kreb's cycle.

7

Sources

Chicken, banana, fortified cereal.

Supplement: pyridoxine hydrochloride

8

RDA

1.3 mg

9

Assessment

Direct: plasma >30 nmol/L

Functional: tryptophan load test measures xanthurenic acid excretion (produced in deficiency)

10

Function

Coenzyme.

AA metabolism.

Niacin synthesis.

Glycogen degradation.

11

Deficiency

Depression, cheilosis, anemia.

Can be caused my riboflavin deficiency.
Mg needed as well to convert PN to PLP.

12

Toxicity

100 mg

Neuropathy, impaired reflexes.

13

Therapy/ megadosing

Carpal tunnel, premenstrual, depression, muscle fatigue