Rand56
Senior Member
- Messages
- 675
- Location
- Myrtle Beach, SC
Anytime I have ever taken P5P, either on it's own or a "bioavailable" B complex that had P5P in it, I've always felt worse in that it made me even more fatigued and made my depression worse. The last couple of days I have substituted regular B-6 pyridoxine in place of the P5P. I'm having a more favorable response to the pyridoxine. I recently tested low in alkaline phosphatase on a blood test, and according to the info on this site..maybe regular B-6 is the way to go for me?
"Only dephosphorylated B6 vitamers can be transported into the cells (Coburn et al., 2003)
indicating that the bioavailability of intact pyridoxal 5’-phosphate upon oral intake would be
low. Removal of the phosphate group is a function of alkaline phosphatases, which are encoded
by at least four different genes producing tissue non specific, intestinal, placental and germ cell
alkaline phosphatases (van Hoof and De Broe, 1994). The tissue non-specific alkaline
phosphatase is the one predominantly involved in vitamin B6 metabolism and it is located
anchored to the ectoplasmic side of the plasma membrane.
Given that the bioavailability of pyridoxal 5’-phosphate requires hydrolysis of the phosphate
group before absorption through the intestinal layer may occur, one can conclude that the
bioavailability of vitamin B6 from pyridoxal 5’-phosphate will be lower than or at best similar
to the bioavailability of pyridoxine."
The above info is in section 4 which is about 2/3 rd's of the way down the page...
http://www.efsa.europa.eu/de/scdocs/doc/760.pdf
If the above info is correct, would I be correct in assuming <no biochemistry wizard here> that since I'm low in alkaline phosphatase, and since only dephosphorylated B6 can be transported into cells, that I'm taxing my already low reserves of alkaline phosphatase and this is the reason why I feel more like dirt when I take P5P? Am I not understanding this correctly?
Is R5P the same in that it also has to be dephosphorylated to be transported into the cell? If so, could also explain why I get a double whammy taking a "bioavailable" B-Complex that also has R5P in it in addition to P5P.
Someone let me know if I'm not understanding this correctly. Thanks
Rand
"Only dephosphorylated B6 vitamers can be transported into the cells (Coburn et al., 2003)
indicating that the bioavailability of intact pyridoxal 5’-phosphate upon oral intake would be
low. Removal of the phosphate group is a function of alkaline phosphatases, which are encoded
by at least four different genes producing tissue non specific, intestinal, placental and germ cell
alkaline phosphatases (van Hoof and De Broe, 1994). The tissue non-specific alkaline
phosphatase is the one predominantly involved in vitamin B6 metabolism and it is located
anchored to the ectoplasmic side of the plasma membrane.
Given that the bioavailability of pyridoxal 5’-phosphate requires hydrolysis of the phosphate
group before absorption through the intestinal layer may occur, one can conclude that the
bioavailability of vitamin B6 from pyridoxal 5’-phosphate will be lower than or at best similar
to the bioavailability of pyridoxine."
The above info is in section 4 which is about 2/3 rd's of the way down the page...
http://www.efsa.europa.eu/de/scdocs/doc/760.pdf
If the above info is correct, would I be correct in assuming <no biochemistry wizard here> that since I'm low in alkaline phosphatase, and since only dephosphorylated B6 can be transported into cells, that I'm taxing my already low reserves of alkaline phosphatase and this is the reason why I feel more like dirt when I take P5P? Am I not understanding this correctly?
Is R5P the same in that it also has to be dephosphorylated to be transported into the cell? If so, could also explain why I get a double whammy taking a "bioavailable" B-Complex that also has R5P in it in addition to P5P.
Someone let me know if I'm not understanding this correctly. Thanks
Rand