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The tissue profile of metabolically active coenzyme forms of vitamin B12 differs in vitamin B12-depleted rats treated with hydroxo-B12 or cyano-B12.
Br J Nutr. 2018 07; 120(1):49-56.BJ

Abstract

Recent rat studies show different tissue distributions of vitamin B12 (B12), administered orally as hydroxo-B12 (HO-B12) (predominant in food) and cyano-B12 (CN-B12) (common in supplements). Here we examine male Wistar rats kept on a low-B12 diet for 4 weeks followed by a 2-week period on diets with HO-B12 (n 9) or CN-B12 (n 9), or maintained on a low-B12 diet (n 9). Plasma B12 was analysed before, during and after the study. The content of B12 and its variants (HO-B12, glutathionyl-B12, CN-B12, 5'-deoxyadenosyl-B12 (ADO-B12), and methyl-B12 (CH3-B12)) were assessed in the tissues at the end of the study. A period of 4 weeks on the low-B12 diet reduced plasma B12 by 58 % (from median 1323 (range 602-1791) to 562 (range 267-865) pmol/l, n 27). After 2 weeks on a high-B12 diet (week 6 v. week 4), plasma B12 increased by 68 % (HO-B12) and 131 % (CN-B12). Total B12 in the tissues accumulated differently: HO-B12>CN-B12 (liver, spleen), HO-B12<CN-B12 (kidneys), and HO-B12≈CN-B12 (brain, heart). Notably, more than half of the administered CN-B12 remained in this form in the kidneys, whereas HO-B12 was largely converted to the bioactive ADO-B12. Only <10 % of the other cofactor, CH3-B12, were found in the tissues. In conclusion, dietary CN-B12 caused a higher increase in plasma and total kidney B12 but provided less than half of the active coenzymes in comparison to dietary HO-B12. These data argue that HO-B12 may provide a better tissue supply of B12 than CN-B12, thereby underscoring the lack of a direct relation between plasma B12 and tissue B12.

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Publisher Full Text (DOI)

Authors+Show Affiliations

Greibe E
1Department of Clinical Biochemistry,Aarhus University Hospital,8200 Aarhus N,Denmark.
Kornerup LS
1Department of Clinical Biochemistry,Aarhus University Hospital,8200 Aarhus N,Denmark.
Juul CB
2Department of Molecular Biology and Genetics,Aarhus University,8000 Aarhus,Denmark.
Fedosov SN
2Department of Molecular Biology and Genetics,Aarhus University,8000 Aarhus,Denmark.
Heegaard CW
2Department of Molecular Biology and Genetics,Aarhus University,8000 Aarhus,Denmark.
Nexo E
1Department of Clinical Biochemistry,Aarhus University Hospital,8200 Aarhus N,Denmark.

MeSH

Animal FeedAnimalsBrainCoenzymesDietDietary SupplementsKidneyLiverMaleRatsRats, WistarTissue DistributionVitamin B 12Vitamin B 12 Deficiency

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

29936920

Citation

Greibe, Eva, et al. "The Tissue Profile of Metabolically Active Coenzyme Forms of Vitamin B12 Differs in Vitamin B12-depleted Rats Treated With hydroxo-B12 or Cyano-B12." The British Journal of Nutrition, vol. 120, no. 1, 2018, pp. 49-56.
Greibe E, Kornerup LS, Juul CB, et al. The tissue profile of metabolically active coenzyme forms of vitamin B12 differs in vitamin B12-depleted rats treated with hydroxo-B12 or cyano-B12. Br J Nutr. 2018;120(1):49-56.
Greibe, E., Kornerup, L. S., Juul, C. B., Fedosov, S. N., Heegaard, C. W., & Nexo, E. (2018). The tissue profile of metabolically active coenzyme forms of vitamin B12 differs in vitamin B12-depleted rats treated with hydroxo-B12 or cyano-B12. The British Journal of Nutrition, 120(1), 49-56. https://doi.org/10.1017/S000711451800123X
Greibe E, et al. The Tissue Profile of Metabolically Active Coenzyme Forms of Vitamin B12 Differs in Vitamin B12-depleted Rats Treated With hydroxo-B12 or Cyano-B12. Br J Nutr. 2018;120(1):49-56. PubMed PMID: 29936920.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The tissue profile of metabolically active coenzyme forms of vitamin B12 differs in vitamin B12-depleted rats treated with hydroxo-B12 or cyano-B12. AU - Greibe,Eva, AU - Kornerup,Linda S, AU - Juul,Christian B, AU - Fedosov,Sergey N, AU - Heegaard,Christian W, AU - Nexo,Ebba, PY - 2018/6/26/entrez PY - 2018/6/26/pubmed PY - 2019/9/4/medline KW - ADO-B12 5'-deoxyadenosyl-B12 KW - B12 vitamin B12 KW - CH3-B12 methyl-B12 KW - CN-B12 cyano-B12 KW - GS-B12 glutathionyl-B12 KW - HO-B12 hydroxo-B12 KW - Active coenzymes KW - Cyanocobalamin KW - Dietary vitamin B12 KW - Hydroxocobalamin KW - Tissue distribution KW - Vitamin B12-depleted rats SP - 49 EP - 56 JF - The British journal of nutrition JO - Br J Nutr VL - 120 IS - 1 N2 - Recent rat studies show different tissue distributions of vitamin B12 (B12), administered orally as hydroxo-B12 (HO-B12) (predominant in food) and cyano-B12 (CN-B12) (common in supplements). Here we examine male Wistar rats kept on a low-B12 diet for 4 weeks followed by a 2-week period on diets with HO-B12 (n 9) or CN-B12 (n 9), or maintained on a low-B12 diet (n 9). Plasma B12 was analysed before, during and after the study. The content of B12 and its variants (HO-B12, glutathionyl-B12, CN-B12, 5'-deoxyadenosyl-B12 (ADO-B12), and methyl-B12 (CH3-B12)) were assessed in the tissues at the end of the study. A period of 4 weeks on the low-B12 diet reduced plasma B12 by 58 % (from median 1323 (range 602-1791) to 562 (range 267-865) pmol/l, n 27). After 2 weeks on a high-B12 diet (week 6 v. week 4), plasma B12 increased by 68 % (HO-B12) and 131 % (CN-B12). Total B12 in the tissues accumulated differently: HO-B12>CN-B12 (liver, spleen), HO-B12<CN-B12 (kidneys), and HO-B12≈CN-B12 (brain, heart). Notably, more than half of the administered CN-B12 remained in this form in the kidneys, whereas HO-B12 was largely converted to the bioactive ADO-B12. Only <10 % of the other cofactor, CH3-B12, were found in the tissues. In conclusion, dietary CN-B12 caused a higher increase in plasma and total kidney B12 but provided less than half of the active coenzymes in comparison to dietary HO-B12. These data argue that HO-B12 may provide a better tissue supply of B12 than CN-B12, thereby underscoring the lack of a direct relation between plasma B12 and tissue B12. SN - 1475-2662 UR - https://www.unboundmedicine.com/medline/citation/29936920/The_tissue_profile_of_metabolically_active_coenzyme_forms_of_vitamin_B12_differs_in_vitamin_B12_depleted_rats_treated_with_hydroxo_B12_or_cyano_B12_ DB - PRIME DP - Unbound Medicine ER -