Fitamin B12: Gwahaniaeth rhwng fersiynau

Mae diffyg y fitamin B₁₂ mewn deiet person yn achosi nifer o afiechydon gan gynnwys anemia megaloblastic.<ref>http://www.foodcomp.dk/v7/fvdb_foodnutrlist.asp?CompId=0049</ref> Gall diffyg fitamin B₁₂ achosi niwed difrifiol a di-droi-nôl, yn enweidg i'r ymenydd a'r system nerfus.<ref>{{cite journal | vauthors = van der Put NM, van Straaten HW, Trijbels FJ, Blom HJ | title = Folate, homocysteine and neural tube defects: an overview | journal = Experimental Biology and Medicine | volume = 226 | issue = 4 | pages = 243–70 | date = April 2001 | pmid = 11368417 | doi = 10.1177/153537020122600402 | url = http://ebm.sagepub.com/content/226/4/243 }}</ref> Ar lefel ychydig yn is na'r normal, gall achosi amrywiaeth o symptomau megis gor-flinder (fatigue meddygol), [[syrthni]], iselder meddwl, cof gwael, colli anadl, cur pen a chroen gwelw yn enwedig mewn pobl dros 60 oed<ref>{{cite web|url=http://www.nhs.uk/Conditions/Anaemia-vitamin-B12-and-folate-deficiency/Pages/Symptoms.aspx|title=Vitamin B₁₂ or folate deficiency anaemia - Symptoms|publisher=National Health Service, England|date=May 16, 2016|access-date=February 16, 2017}}</ref> whosy'n producecreu lessllai stomacho acidasid asyn theyy agestumog wrth iddynt heneiddio, therebya felly, yn cynyddu y increasingtebygolrwydd theiro probabilityddiffyg ofFitamin B₁₂ deficiencies.<ref name="nih" /> Gall diffyg Fitamin B₁₂ hefyd achosi symptomau o [[mania]] a [[psychosis]].<ref name="imajvitaminb12">{{cite journal | vauthors = Masalha R, Chudakov B, Muhamad M, Rudoy I, Volkov I, Wirguin I | title = Cobalamin-responsive psychosis as the sole manifestation of vitamin B12 deficiency | journal = The Israel Medical Association Journal | volume = 3 | issue = 9 | pages = 701–3 | date = September 2001 | pmid = 11574992 | url = http://www.ima.org.il/IMAJ/ViewArticle.aspx?year=2001&month=09&page=701 }}</ref>