1. Vitamin B-6 Caitlyn Beck

2. Vitamin B-6 Overview  B-6 is a family of 3 compounds: pyridoxal, pyridoxine, and pyridoxamine.  All 3 can become active B-6 coenzymes  Pyridoxal Phosphate (PLP)  B-6 or Pyridoxine

3. Vitamin B-6 in Foods  Stored in muscle tissues of animals  More readily absorbed  Whole-grains  Leading sources in US: fortified ready-to- eat cereals, poultry, beef, potatoes and bananas.  Can be lost when foods exposed to heat and other processing

4. Vitamin B-6 Needs  RDA 1.3 mg/day for men and woman up to age 50  For older adults, RDA increases 1.7 mg/day for men, 1.5 mg/day for momen  Daily Value= 2 mg  Average daily intake is 2.5 mg in adult men, and 1.7 mg for women

5. Vitamin B-6 Upper Level  Upper Level for adults 100 mg/day  Vitamin B-6 supplements  Irreversible nerve damage  Bodybuilders, women attempting to treat for PMS  Painful skin patches, extreme sensitivity to sunlight, nausea, and heartburn

6. Absorption, Transport, Storage and Excretion of B-6  Absorption is by passive diffusion  Coenzyme form converted to free vitamin form for absorption Portal vein Liver Blood  Muscle tissue main storage site  Excess B-6 generally excreted in urine phosphorylated Albumin

7. Functions of B-6: Metabolism  Amino acid metabolism  Coenzyme for transamination reactions that transfer amino groups– allows synthesis of nonessential amino acids  Without PLP, every amino acid would be essential  PLP helps convert homocysteine to amino acid cysteine  PLP required for release of glucose from glycogen  Helps to maintain blood glucose concentration

9. Functions of B-6: Synthesis of Compounds  PLP catalyzes a step in the synthesis of heme  PLP required for synthesis of several neurotransmitters  Serotonin, dopamine, norepinephrine, gamma-aminobutyric acid, histamine  PLP in Vitamin formation

10. Other Vitamin B-6 Functions  Normal immune function  Regulation of gene expression  Effects on health:  Cancer  Cognitive function  Carpal tunnel syndrome  Premenstrual syndrome  Nausea and vomiting in pregnancy

11. Vitamin B-6 Deficiency  Rare in North America  Symptoms:  Seborrheic dermatitis, microcytic hypochromic anemia, convulsions, depression, confusion  Elderly, blacks, smokers, users of oral contraceptive agents, alcoholics, underweight or consume poor diets  Medications

12. Pharmacological Use  Supplemental vitamin B-6 has a long history as a treatment for:  Carpal tunnel syndrome  Premenstrual syndrome (PMS)  Nausea during pregnancy

13. EAL Study on Vitamin B-6  Does supplemental folate and/or Vitamins B6 and B12 reduce homocysteine levels and subsequently reduce coronary events?  Homocysteine relationship with the development of brain disorders, bone disorders and cardiovascular disease

14. 553 patients with successful angioplasty Homocysteine- lowering therapy (272 patients) Placebo (281 patients) Result: Lower serum homocysteine levels in supplemental group vs. control group Schnyder et al (2002)

15. 98,462 female RNs; 30-55 yrs old 658 incident cases of nonfatal MI 281 cases of fatal CHD Controlling for CVD risk factors Risk of CHD lowered with high intake of folate & B-6 Rimm et al (1998) Result: Intake of folate and vitamin B-6 above the current recommended dietary allowance may be important in the primary prevention of CHD among women. Risk of CHD reduced w/ folate & B-6 MV

16. 2,954 people with nondisabling ischemic stroke Low dose group (200 µg pyridoxine) High dose group (25 mg pyridoxine) Toole et al (2004) Result: Both decreased total serum homocysteine, however, the high vitamin dose group had a larger decrease at one month, one year, and 2 years.

17. In Conclusion… Supplemental folate and/or Vitamins B6 and B12 reduced homocysteine levels but there was no significant evidence that it also subsequently reduced coronary heart events.

18. QUESTION TIME!

19. How is the pyridoxal phosphate (PLP) coenzyme used in amino acid metabolism? MAJOR ROLE! Coenzyme for transamination reactions that transfer amino groups to allow the synthesis of nonessential amino acids. Convert homocysteine to the amino acid cysteine. Release of glucose from glycogen– maintain blood glucose concentration

20. What are some good food sources of Vitamin B-6? Fortified ready-to-eat cereals Poultry, beef, fish Potatoes Bananas

21. What are some signs of Vitamin B-6 deficiency? Seborrheic dermatitis Microcytic hypochromic anemia Convulsions Depression Confusion

22. Resources  Wardlaw, G. M. (2013). Wardlaw's Perspectives in Nutrition, 9th edition. New York: McGraw-Hill.  Academy of Nutrition and Dietetics. Does supplemental folate and/or Vitamins B6 and B12 reduce homocysteine levels and subsequently reduce coronary events? Retrieved September 2013, from Evidence Analysis Library: http://andevidencelibrary.com/evidence.cfm?evidence_summar y_id=98&auth=1  Schnyder. Effect of homocysteine-lowering therapy with folic acid, vitamin B12, and vitamin B6 on clinical outcome after percutaneous coronary intervention: the Swiss Heart study: a randomized control trial. JAMA 2002; 288: 973-9.  Rimm EB, et al. Folate andvitamin B-6 from diet and supplements in relation to risk of coronary heart disease among women. JAMA. 1998 Feb 4; 279 (5): 359-364  Toole. Lowering homocysteine in patients with stroke to prevent recurrent stroke, myocardial infarction, and death: The Vitamin Intervention for Stroke Prevention (VISP) Randomized Controlled Trial. JAMA 2004; 291: 565-75.  http://ods.od.nih.gov/factsheets/VitaminB6-QuickFacts/