Vitamin B6

1
Vitamin B6

• Formspyridoxal , pyridoxine ,pyridoxamine
• Active form PLP (pyridoxal 5-phosphate)
• As a coenzyme ? amino acid and protein metabolism
  
• 19781985 Driskell
• Elder and adolescent girl ?Vit.B6 deficiency
  risk group
• 1985 Thanassi Low Vit B6 intake ? cancer
• 1985 Willett Low Vit B6 intake ?CHD

2
Vitamin B6 measures

• 1.plasma PLP
• (1)diet Vit.B6 ?plasma PLP???????
• (2)1993 Mascher
• half-lifelt48 hr ? ??short-term
  intake
• (3)1984 Schuster 19 adults
• plasma PLP and diet intake ? r
  0.61
• (4)1985 Willett 280 men and women by FFQ for
  1yr
• diet intake and fasting plasma PLP?
  r 0.37 (?)
• 
  r 0.39 (?)

3
Vitamin B6 measures

• 2. ??24-hour??
• Vit. B6 ??????4PA(4-pyridoxic acid)
• r 0.72
• 3.erythrocyte transaminase
• (1)glutamate oxaloacetate transaminase
• (2)asparate aminotransferase
• 1992 Lie 265 women r0.65
• 4.tryptophan load test
• ??24-hour?? ? tryptophan metabolites

4
Vitamin B6

• methods
• 1984 Sauberlich
• HPLC ?separate and quantitate different
  vitamin B6
• Storage
• 1984 Howard plasma PLP?frozen at -20C?700 days
• (decline rate 2.2 per year)
• 1983 Camp plasma PLP? frozen at -80C? 10 days

5
Vitamin B6 measures

• 1985 Willett
• Plasma PLP ?age, gender, obesity ????????
• 10?men (20-30yrs) and 10?men (60-70yrs)
• ?plasma PLP level no difference
• 1985 Leklem 1987 Manore
• ?????plasma PLP and urinary Vit.B6 ??????
• 1985 Miller
• ????occ and ??????estrogen???Vit.B6???????
• 1985 Bhagavan
• Drugs and ethanol ?lower plasma PLP level
• 1990 Leklem
• Increase Protein intake and smoking ? lower
  plasma PLP level

6
Calcium

• 1984 McCarron
• dietary calcium ?protects against
  hypertension
• 1985 Garland
• dietary calcium ?protects against colorectal
  cancer
• dietary calcium and osteoporosis , fracture(?)
• Blood calcium level ? homeostatic control

7
Calcium

• Relation between Calcium intake and urinary
  calcium level(?)
• 1985 Castenmiller
• Low-Ca diet? urinary calcium excretion
  
• (???????75)
• Na supplementation ? urinary calcium
  excretion ?
• 1988 Aalberts 22? omnivorous , healthy male
• 1.12 g Ca/day(?92) ? urinary calcium
  excretion (?20)
• 1994 Joseph r 0.05 (127 men)
• r 0.16 (193 women)