how to prevent kidney stone formation i got asked in sci med nutrition about vitamin c and oxalate production toxic kidney stone formation i decided to post my answer here as well because of the recent question about kidney stones not long after i got into sci med i got flamed by a medical fellow for stating that magnesium would prevent kidney stone formation i m going to state it again here but the best way to prevent kidney stones from forming is to take b supplements read on to find out why i have my asbestos suit on now guys vitamin c will form oxalic acid but large doses are needed above grams per day review article nutritional factors in calcium containing kidney stones with particular emphasis on vitamin c int clin nutr rev but glycine also forms oxalic acid d amino acid oxidases for both glycine and vitamin c one of the best ways to drastically reduce this production is not to cut back on dietary intake of vitamin c or glycine but to increase your intake of vitamin b control of hyperoxaluria with large doses of pyridoxine in patients with kidney stones int urol nephrol to mg of b each day significasntly decreased the urinary excretion of oxalate over the month treatment program the action of pyridoxine in primary hyperoxaluria clin sci patients receiving at least mg b each day showed a significant reduction in urinary oxalate levels for gylcine this effect is due to increased transaminase activity b is required for transaminase activity which makes less glycine available for oxidative deamination d amino acid oxidases for vitamin c the effect is quite different there are different pathways for vitamin c catabolism the pathway that leads to oxalic acid formation will usually have to of the ingested dose going into oxalic acid but this is highly variable and the vitamin c review article pointed out that unless the dose gets upto grams per day not too much vitamin c gets catabolized to form oxalic acid at very high doses of vitamin c above grams per day more of the extra vitamin c more than conversion can end up as oxalic acid in a very early study on vitamin c and oxalic production proc soc exp biol med intakes of grams per day up to grams per day increased the average oxalic acid excretion from mg per day up to mg per day until grams per day was reached the average excreted was increased by only to mg per day gram dose gram dose gram dose and gram dose grams jumped it to mg over the average excretion before supplementation and grams jumped it to mg over the average before supplementation b is required by more enzymes than any other vitamin in the body there are probably some enzymes that require vitamin b that we don t know about yet vitamin c catabolism is still not completely understood but the speculation is that this other pathway that does not form oxalic acid must have an enzyme in it that requires b differences in b levels could then explain the very variable production of oxalic acid from a vitamin c challenge this is not the preferred route of catabolism increasing your intake of b would then result in less oxalic acid being formmed if you take vitamin c supplements since the typical american diet is deficient in b some researchers believe that the main cause of calcium oxalate kidney stones is b deficiency especially since so little oxalic acid gets absorbed from the gut diets providing to mg of oxalic acid per day showed absolutely no change in urinary excretion of oxalate urol int if mg was present each day there was a significant increase in urinary oxalate excretion here are the high oxalate foods beans coca instant coffee parsley rhubarb spinach and tea contain at least mg grams beet tops carrots celery chocolate cumber grapefruit kale peanuts pepper sweet potatoe contain to mg grams if the threshold is mg per day you can see that you really have a lot of latitude in food selection a recent n eng j med article also points out that one good way to prevent kidney stone formation is to increase your intake of calcium which will prevent most of the dietary oxalate from being absorbed at all if you also increase your intake of b you shouldn t have to worry about kidney stones at all the rda for b is mg per day for males and mg per day for females directly related to protein intake b can be toxic nerve damage if it is consumed in doses of mg or more per day for an extended peroid weeks to months the usda food survey done in had an average intake of mg per day for males and mg per day for females living in the u s coupled with this low intake was a high protein diet which greatly increases the b requirement as well as the presence of some of the different drugs that either block b absorption are metabolic antagonists of b or promote b excretion in the urine common ones are birth control pills alcohol isoniazid penicillamine and corticosteroids i tell my students to supplement all their patients that are going to get any of the drugs that increase the b requirement the dose recommended for patients taking birth control pills is mg per day and this should work for most of the other drugs that increase the b requirement this would be on top of your dietary intake of b any patient that has a history of kidney stone formation should be given b supplements one other good way to prevent kidney stone formation is to make sure your ca mg dietary ratio is magnesium oxalate is much more soluble than is calcium oxalate the magnesium calcium ratio in the concentrated urines of patients with calcium oxalate calculi invest urol effect of magnesium citrate and magnesium oxide on the crystallization of calcium in urine changes producted by food magnesium interaction j urol review article magnesium in the physiopathology and treatment of renal calcium stones j presse med there are actually about three times as many articles published in the medical literature on the role of magnesium in preventing kidney stone formation than there are for b i thought that i was being pretty safe in stating that magnesium would prevent kidney stone formation in an earlier post in this news group but good old john a in mass jumped all over me i guess that he doesn t read the medical literature oh well since kidney stones can be a real pain and a lot of people suffer from them i thought i d tell you how you can avoid the pain and stay out of the doctor s office martin banschbach ph d professor of biochemistry and chairman department of biochemistry and microbiology osu college of osteopathic medicine w th street tulsa ok without discourse there is no remembering without remembering there is no learning without learning there is only ignorance from a wise man who lived in china many many years ago i think that it still has meaning in today s world
