Dietary Intake of Vitamin B12 is Better for Restoring a Low B12 Status Than a Daily High-Dose Vitamin Pill: An Experimental Study in Rats

Abstract

Vitamin B12 (B12) is present in foods of animal origin, and vegans are encouraged to take supplements with synthetic B12 in order to ensure a sufficient uptake. Recent rat studies suggest that natural (hydroxo-B12, HO-B12) and synthetic (cyano-B12, CN-B12) B12 behave differently in the body. Here, we test if a daily vitamin pill matches dietary B12 in ability to restore a low B12 status in rats. B12-depleted male Wistar rats (n = 60) were divided into five groups (n = 12 in each) and subjected to two weeks intervention with various schemes of B12 supplementation. Two “dietary” groups received a low-B12 chow that was fortified with either HO-B12 or CN-B12 providing a continuous supply. Two “pill” groups received a single daily dose of CN-B12, where the vitamin content either matched or exceeded by factor four the provisions for the “dietary” groups. A control group received the low-B12 chow without B12 fortification. B12 was measured in plasma and tissues. Dietary B12 provides 35% more B12 to the tissues than an equivalent single daily dose (p < 0.0001). Natural B12 delivers 25% more B12 to the liver than synthetic B12 (p = 0.0007). A fourfold increase in B12, supplemented as a single daily dose, does not provide any extra B12 to the tissues (p = 0.45). We conclude that dietary B12 is better at rescuing a low B12 status than a daily vitamin pill.

Intracellular and Tissue Levels of Vitamin B12 in Hepatocytes Are Modulated by CD320 Receptor and TCN2 Transporter

“…The saturable character of B12 uptake was also found in the intestine [ 21 ], though up- and downregulation of transporters was not demonstrated. A study in the rat model showed that several small doses of dietary B12 are more efficient in increasing blood and tissue B12, than a single large dose [ 11 ]. In a human study, Yajnik et al showed that supplementation with a physiological dose of oral B12 over 11-months in asymptomatic low B12 adolescent women significantly improved the B12 levels in these women.…”

“…Studies have also shown that CD320 knockout mice have B12 deficiency and have behavioural abnormalities, macrocytic anaemia, infertility and hypomethylation of DNA in the brain [ 8 ]. However, current knowledge on the absorption and tissue distribution of B12 has only been reported in few animal studies [ 9 , 10 , 11 , 12 , 13 , 14 ]. A study in Wistar rats showed that kidneys contained more B12 compared to other tissues such as lungs, spleen, brain, heart and liver [ 15 ].…”

Nutritional 1C Imbalance, B12 Tissue Accumulation, and Pregnancy Outcomes: An Experimental Study in Rats

“…Accumulation of [ 57 Co]B12 in fetuses and maternal tissue were assessed by counting of the whole organs for 1 min in a gamma counter (2470 Wizard 2 Automatic Gamma Counter, Perkin Elmer, Skovlunde, Denmark) as described in [ 8 , 9 , 15 ]. In practice, the tissues were thawed on ice, cut into smaller pieces, and transferred to tubes for the gamma counter.…”

Study of the protective effects of cyanocobalamin on methotrexate induced nephrotoxicity in rats

“…10 Vitamin B12 has several functions in methylation reactions in the body, acts as a cofactor in the form of methylcoblamin by the conversion of homocysteine to methionine and in the form of adenosylcobalamin in the transformation of methylmalonyl-CoA to succinyl-CoA. Both of these chemical reactions are important for cell division and growth, 11 Vitamin B12 plays a role in erythropoiesis and healthy neurological functions, 12 and it proved useful in the treatment of many diseases associated with inflammatory and oxidative stress. 13 The FDA have stated that cyanocobalamin is safe, there is no toxicity reported when cyanocobalamin given to animals, even at several thousand times their nutritional requirements.…”