Relationship between Vitamin B12 and Cobalt Metabolism in Domestic Ruminant: An Update

Abstract

Cobalt, as a trace element, is essential for rumen microorganisms for the formation of vitamin B12. In the metabolism of mammals, vitamin B12 is an essential part of two enzymatic systems involved in multiple metabolic reactions, such as in the metabolism of carbohydrates, lipids, some amino acids and DNA. Adenosylcobalamin and methylcobalamin are coenzymes of methylmalonyl coenzyme A (CoA) mutase and methionine synthetase and are essential for obtaining energy through ruminal metabolism. Signs of cobalt deficiency range from hyporexia, reduced growth and weight loss to liver steatosis, anemia, impaired immune function, impaired reproductive function and even death. Cobalt status in ruminant animals can be assessed by direct measurement of blood or tissue concentrations of cobalt or vitamin B12, as well as the level of methylmalonic acid, homocysteine or transcobalamin in blood; methylmalonic acid in urine; some variables hematological; food consumption or growth of animals. In general, it is assumed that the requirement for cobalt (Co) is expressed around 0.11 ppm (mg/kg) in the dry matter (DM) diet; current recommendations seem to advise increasing Co supplementation and placing it around 0.20 mg Co/kg DM. Although there is no unanimous criterion about milk production, fattening or reproductive rates in response to increased supplementation with Co, in some investigations, when the total Co of the diet was approximately 1 to 1.3 ppm (mg/kg), maximum responses were observed in the milk production.

Sex differences in the link between blood cobalt concentrations and insulin resistance in adults without diabetes

“…Excess cobalt exposure, such as during the treatment of cell lines or mice with excessive cobalt chloride, may act as a hypoxia-mimetic agent that can inhibit adiponectin transcription, thus contributing to the development of IR in vitro [26] and in vivo [27]. Symptoms of cobalt deficiency include hypoxia, growth retardation, weight loss, hepatic steatosis, anemia, immune dysfunction, reproductive dysfunction, and even death [28]. Low-dose cobalt, as a trace element, has been shown to assemble into enzymes such as cobalt protoporphyrin and attenuate IR [29] and improve insulin sensitivity [30,31] in mice.…”

Microbial and Genetic Resources for Cobalamin (Vitamin B12) Biosynthesis: From Ecosystems to Industrial Biotechnology

“…As for the gut microbiota of ruminants, the majour species Selenomonas ruminantium , Megasphaera elsdenii , Butyrivibrio fibrisolvens, Prevotella spp. and some unidentified species, which habitat the rumen, have been shown to provide the largest amounts of the coenzyme B12 and analogues, while the increase in Bacteroidetes , Ruminiclostridium , Butyrivibrio , and Succinimonas and Succinivibrionaceae species correlate with lower concentrations of vitamin B12, indicating their complete or partial auxothrophy [ 87 ]. Ruminants have higher vitamin B12 requirements than nonruminants due to their active propionic acid metabolism; therefore, the arising B12 requirenment is satisfied by an increase in Co 2+ supplementation for stimulation of B12 biosynthesis in their mutualistic bacteria [ 87 ].…”

“…The essential metabolites of the B12 coenzyme family for mammals are synthesized only by gut microbiota [ 66 ]. However, the microbial production of vitamin B12 plays only a limited role because of its restricted availability in the environment, including ruminants particularly juveniles [ 87 ]. This can only result from lysis of the microbes that produce B12 or specific behaviors of the hosts, such as coprophagy [ 6 ].…”

“…As feed additives, vitamin B12 is mainly used for pigs, poultry and calves, suggesting that their own microbiota does not provide sufficient amount of the coenzyme in contrast to ruminants [ 6 , 54 ]. However, ruminants also mostly need to uptake the exogenous vitamin B12 [ 66 , 87 ]. The dosage levels of all animal feeds in Europe and US lies between 10 and 30 mg/t.…”

Refining Knowledge of Factors Affecting Vitamin B12 Concentration in Bovine Milk

“…Indeed, vitamin B 12 is solely synthesized by bacteria and archaea when cobalt is not limiting [ 8 ]. Bacteria and archaea living in the rumen are able to synthesize vitamin B 12 , which is ultimately secreted in milk [ 9 ]. Animal products, especially those from ruminants, are an excellent source of vitamin B 12 , whereas plant-based products, such as soy beverage do not contain it unless they are fortified with the synthetic form of the vitamin.…”