Editing Chocolate milk (section)

===Calcium oxalate production===
Chocolate has [[oxalic acid]], which reacts with the [[calcium]] in the milk producing [[calcium oxalate]], thus preventing the calcium from being absorbed in the intestine. However, it is present in small enough amounts that the effect on calcium absorption is negligible (2–3%).<ref>{{cite web |last=Gilbert |first=Sue |url=http://parenting.ivillage.com/tp/tpnutrition/0,,3vpm,00.html |url-status=dead |archive-url=https://web.archive.org/web/20050901001826/http://parenting.ivillage.com/tp/tpnutrition/0,,3vpm,00.html |archive-date=1 September 2005 |title=Does putting chocolate in milk decrease calcium absorption? |website=iVillage.com}}</ref> As chocolate contains relatively small amounts of oxalate, it is unclear to what extent chocolate consumption affects healthy people with calcium-rich diets. 

In a 2008 study, participants who consumed one or more servings of chocolate on a daily basis had lower bone density and strength than those participants who ate a serving of chocolate six times a week or less. Researchers believe this may be due to oxalate inhibiting calcium absorption – but it could also be due to sugar content in chocolate, which may increase calcium excretion. It is clear, however, that consuming foods high in oxalate – and in turn their effect on calcium absorption – is a more significant concern for people with oxalate [[kidney stones]], which occur when there is too much oxalate in the [[urine]]. These people especially should reduce their oxalate intake and increase their calcium intake.<ref>Katherine Zeratsky, [http://www.mayoclinic.com/health/calcium/AN01294 "Chocolate: Does it impair calcium absorption?"], mayoclinic.com</ref> However, the high [[magnesium]] content in chocolate is likely to reduce the risk of stone formation, because like [[citrate]], magnesium is also an inhibitor of urinary crystal formation.<ref>{{cite journal|last=Johri|first=N.|author2=Cooper, B.|author3=Robertson, W.|author4=Choong, S.|author5=Rickards, D.|author6=Unwin, R.|title=An update and practical guide to renal stone management|journal=Nephron Clinical Practice|volume=116|issue=3|pages=c159–71|year=2010|pmid=20606476|doi=10.1159/000317196|url=https://www.karger.com/Article/PDF/000317196|doi-access=free}}</ref>