re magnesium absorption cofactors (b6) in the context of dietary restrictions:http://lpi.oregonstate.edu/infocenter/v ... vitaminB6/
Certain plant foods contain a unique form of vitamin B6 called pyridoxine glucoside; this form of vitamin B6 appears to be only about half as bioavailable as vitamin B6 from other food sources or supplements. Vitamin B6 in a mixed diet has been found to be approximately 75% bioavailable (7). In most cases, including foods in the diet that are rich in vitamin B6 should supply enough to prevent deficiency. However, those who follow a very restricted vegetarian diet might need to increase their vitamin B6 intake by eating foods fortified with vitamin B6 or by taking a supplement.
Bioavailability of vitamin B-6 from plant foodshttp://ajcn.nutrition.org/content/48/3/863.abstract
The major factors that affect bioavailability of vitamin B-6 are formation of reaction products during food processing, fiber type and content, and presence of the conjugated pyridoxine glucoside. The bioavailability of vitamin B-6 from animal products is quite high, reaching 100% for many foods. In general the bioavailability from plant foods is lower. The presence of fiber reduces the bioavailability by 5-10% whereas the presence of pyridoxine glucoside reduces the bioavailability by 75-80%. This glucoside is found in a variety of plant foods, with the highest content occurring in the crucifers
. The percent of total vitamin B-6 that exists as the glucoside has been suggested to be the best indicator of bioavailability. Data from Nepalese vegetarian lactating women suggest that the low vitamin B-6 status of these mothers and their infants, as determined by their concentrations of plasma pyridoxal phosphate, may be adversely affected by the dietary intake of the naturally occurring pyridoxine glucoside.http://www.whfoods.com/genpage.php?tnam ... t&dbid=108
Spinach....................1 cup cooked...0.44 22% DV [35% glucoside so likely a significant impact on bioavailability of that .44mgs of b6]
Bell Peppers..............1 cup raw.......0.27 13.5% DV
Turnip Greens...........1 cup cooked...0.26 13% DV
Summer Squash........1 cup raw.......0.25 12.5% DV
Mushrooms, Shiitake..87 g...............0.25 12.5% DV
(so far I have no data on glucoside content for the last four)
so anyway, let's say you eat all of that, twice over, *every single day*, you *might* get close to 100% of RDA. and whether you are satisfied with that depends on whether you feel the RDA of two whole milligrams is actually valid.
for comparison's sake, non vegans can get away with things like 4oz tuna, which delivers close to 60% of RDA in one shot. or chicken which delivers 35% of RDA in one 4oz serving. both with close to 100% bioavailability.
so yep looks like given anon's decisions re animal products, a b6 supplement looks pretty smart to help with her absorption and utilization of mag from food and/or supplements.
(on a related note, watch the cauliflower for boosting O-3, anon.. looks like raw is the way to go there. has 5% glucoside but somehow frozen cauli has the highest glucoside fraction of all in this study.. 63-82%!)
I have never looked into optimal serum targets for b6, but I do know b6 formed an important component of the klenner protocol (my little fakey modified version that is) that helped me so much when I was first diagnosed and working on coming off my vegan diet. might be interesting to get a handle on the state of the research on this one. not this week though!! ugh where did the morning go!?!