# Iron Supplements linked to kidney stones? **URL:** \ **Category:** Factual Questions\ **Created:** [December 17, 2005, 1:14pm UTC](https://boards.straightdope.com/t/iron-supplements-linked-to-kidney-stones/336049 "2005-12-17T13:14:39Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Khadaji](https://avatars.discourse-cdn.com/v4/letter/k/9e8a1a/32.png) [@Khadaji](https://boards.straightdope.com/u/Khadaji)\ **Post date:** [December 17, 2005, 1:14pm UTC](https://boards.straightdope.com/t/iron-supplements-linked-to-kidney-stones/336049/1 "2005-12-17T13:14:39Z")
I recently had the pleasure of Kidney Stones. They have passed, but while recently discussing them with co-workers, one of the men claimed that taking iron supplements has been linked to having them? Anyone else hear this? Anyone able to provide a cite? Thanks! ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [December 17, 2005, 3:09pm UTC](https://boards.straightdope.com/t/iron-supplements-linked-to-kidney-stones/336049/2 "2005-12-17T15:09:34Z")
> [@Khadaji](#): > > I recently had the pleasure of Kidney Stones. They have passed, but while recently discussing them with co-workers, one of the men claimed that taking iron supplements has been linked to having them? > > Anyone else hear this? Anyone able to provide a cite? > > Thanks! Never heard of this. Sometimes iron is given to help reduce oxalate levels, in the theory that if one produces oxalate stones, it might help. Also, if one is on urease inhibitors to try to dissolve struvite stones, one must avoid iron. If you want the real low-down on what to do for kidney stones, read this thread: [http://boards.straightdope.com/sdmb...ad.php?t=246401](http://boards.straightdope.com/sdmb...ad.php?t=246401) Briefly, it says > [@QtM](#): > > a competent doc should be able to test your stone to determine its type, test your urine for critical high and/or low levels of key metabolites, and suggest a dietary change/medication addition which could prevent future stone formation, and which could dissolve stones which are still sitting in the kidney and not yet causing problems. > > Uric acid stones can often be avoided by maintaining urine pH in the 6.5 to 7 range. Sodium or potassium citrate is often used to do this. If the stones are forming because of excess excretion of urate, restriction of dietary proteins may help. If not, then allopurinol might prevent future stone formation too. > > Pure calcium phosphate stones are uncommon and need further medical evaluation to determine why one is forming them. > > Mixed calcium phosphate & oxalate stones have a number of possible causes. All with different treatments. > > If they form because of concentrated urine, drink more fluid. If they form because there is excess calcium in the urine, then calcium levels in the blood should be checked. If blood calcium levels are normal, you actually probably need more dietary calcium, but in a form that’s retained in your body better, and not as calcium supplement tabs. If that fails, your doctor might recommend urine acidification or other drug therapy, like hydrochlorothiazide. > > But: If your mixed calcium phosphate and oxalate stones form because you are putting too much oxalate in your urine, then treatment will depend on just how much excess oxalate is in your urine. If only mildly elevated, you just might need to lower the oxalate in your diet and make sure you’re getting less than 2 grams of vitamin C a day. If medium, you might need an agent to bind the oxalate in your gut, and not let your body absorb so much. Cholestyramine works for this purpose. If real high, you may need high dose vitamin B 6 (pyridoxine) to to control it, and your liver should probably be evaluated to see why you put out so much oxalate. > > However: If your mixed calcium phosphate and oxalate stones are a result of low levels of citrate in the urine, then merely adding potassium citrate to your diet should suffice. > > Oddly enough: Sometimes, the first-mentioned excess urate in the urine causes not uric acid stones, but mixed calcium phosphate and oxalate stones! (is it not to laugh?) If that is what is occurring, then go ahead and treat with the measures recommended for treating uric acid stones. > > Now: There are a myriad of cases which are not so clear-cut as the above, so I won’t get into them here. > > In the meantime: Drink lots of water!!! > > BTW, here’s a rather technical link which helps one figure out what to do based on what type of stone, with a bit of background epidemiology. > > [http://fpnotebook.com/URO107.htm](http://fpnotebook.com/URO107.htm) ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [December 17, 2005, 3:13pm UTC](https://boards.straightdope.com/t/iron-supplements-linked-to-kidney-stones/336049/3 "2005-12-17T15:13:02Z")
also: > [@QtM](#): > > And here’s the official website on kidney stones from the NIH, nicely broken into language more coherent than mine for the educated layman. [http://kidney.niddk.nih.gov/kudisea...s/stonesadults/](http://kidney.niddk.nih.gov/kudisea...s/stonesadults/) and > [@](#): > > Mixed calcium stones are the most common type, representing 75-90% of all kidney stones. > > Of those type of stones, about 30-50% are due to over-concentrated urine. In other words, drink more fluid! > > Another 50% are due to excess calcium in the urine. If excess calcium is also present in the blood, hyperparathyroidism is the most common cause of that problem. However, excess vitamin D consumption, sarcoid disease, metastatic cancer, steroid use and Pagets disease should be considered. > > If the calcium level in the blood is normal while excess calcium is in the urine, the most likely reason is too much elemental calcium in the diet. The next most likely reason is idiopathic urinary calcium elevation (which means it’s high and we don’t know why ). Renal tubule acidosis and Dent’s disease are possible causes but uncommon. > > Excessive urate or oxalate in the urine, or reduced citrate in the urine, account for the majority of the remaining 20% or so of mixed calcium stones.