title: Relationship between soil cobalt and vitamin B12 levels in the liver of livestock in Saudi Arabia: role of competing elements in soils.
abstract: OBJECTIVE
  This study aimed to analyze the agricultural soils from different regions in Saudi Arabia for cobalt and related metals as Cu(2+), Ni(2+), Cr(3+), Zn(2+) and Pb(2+).
  
  
  METHODS
  Liver and muscle tissues of livestock grazing on the selected areas were analyzed for the content of Co and vitamin B12.
  
  
  RESULTS
  Our results indicated that the levels of Co in surface soil (0-15 cm) were higher than in sub-surface soil (>15 cm-45 cm). In contrast, Pb and Zn were higher in sub-surface soil than in surface soil. A significant positive correlation existed between the levels of Co and vitamin B12 in the liver of livestock. However, Co was not detected in muscle tissues while vitamin B12 was present at very low levels in comparison with the levels found in the liver. The results indicated that Zn(2+), Pb(2+) compete with Co in soil, which eventually affected the levels of vitamin B12 in liver.
  
  
  CONCLUSIONS
  It was recommended that survey of heavy metals in grazing fields of cattle should consider inclusion of multiple elements that compete with the bioavailability of essential elements in plants and animals for the prevention of deficiency of essential elements such as Co.
authors.affiliation: Biochemistry Department, Faculty of Science King Abdulaziz University, Jeddah, Saudi Arabia; Experimental Biochemistry Unit, King Fahd Medical Research Center. King Abdulaziz University; Vitamin D Pharmacogenomics Research Group, King Abdulaziz University.
authors.forename: Etimad A
authors.initials: EA
authors.lastname: Huwait
authors.affiliation: Biochemistry Department, Faculty of Science King Abdulaziz University, Jeddah, Saudi Arabia; Experimental Biochemistry Unit, King Fahd Medical Research Center. King Abdulaziz University; Productions of Bioproducts for Industrial Applications Research Group, King Abdulaziz University.
authors.forename: Taha A
authors.initials: TA
authors.lastname: Kumosani
authors.affiliation: Biochemistry Department, Faculty of Science King Abdulaziz University, Jeddah, Saudi Arabia; Experimental Biochemistry Unit, King Fahd Medical Research Center. King Abdulaziz University; Bioactive Natural Products Research Group, King Abdulaziz University; Biochemistry Department, Faculty of Science, Ain Shams University, Cairo, Egypt.
authors.forename: Said S
authors.initials: SS
authors.lastname: Moselhy
authors.affiliation: Biochemistry Department, Faculty of Science King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Rami M
authors.initials: RM
authors.lastname: Mosaoa
authors.affiliation: Experimental Biochemistry Unit, King Fahd Medical Research Center. King Abdulaziz University; Productions of Bioproducts for Industrial Applications Research Group, King Abdulaziz University.
authors.forename: Soonham S
authors.initials: SS
authors.lastname: Yaghmoor
mesh_terms: D000383:Agriculture; D000818:Animals; D002417:Cattle; D003035:Cobalt; D004784:Environmental Monitoring; D006801:Humans; D008099:Liver / Q000378:metabolism*; D058751:Livestock; D019216:Metals, Heavy / Q000032:analysis*; D009930:Organic Chemicals / Q000032:analysis; D012529:Saudi Arabia; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D014805:Vitamin B 12 / Q000378:metabolism*
chemical_list: D019216:Metals, Heavy; D009930:Organic Chemicals; D012987:Soil; D012989:Soil Pollutants; D003035:Cobalt; D014805:Vitamin B 12
keywords: Soil; cattle; cobalt; transfer; uptake; vitamin B12