Bioavailability of dietary cyanocobalamin (vitamin B12) in growing pigs1

Abstract

The present project aimed to estimate bioavailability of dietary vitamin B(12), for which little information is available in growing pigs. Two approaches, each using 2 quantities of dietary cyanocobalamin, were compared; the first was based on whole body retention for 8 d and the second was based on nycthemeral portal net flux of vitamin B(12). In the first trial, 15 blocks of 3 pigs (31.7 ± 0.5 kg of BW) were formed according to their vitamin B(12) status. Within each block, 1 pig (CONT) was killed and tissues were sampled for vitamin B(12) determination. The remaining 2 piglets were fed 25 (B(12)-25) or 250 (B(12)-250) μg daily of cyanocobalamin for 8 d. Urine was sampled twice daily, and the pigs were killed and sampled as CONT pigs. The total content of vitamin B(12) in the carcass, urine, and intestinal tract was affected by the dietary treatments (P < 0.01) but not in the liver (P > 0.019). The whole body retention of vitamin B(12) was greater (P = 0.02) in B(12)-250 than B(12)-25 pigs, but the corresponding bioavailability was estimated to be 5.3 and 38.2%, respectively. In trial 2, 11 pigs (35.1 ± 4.0 kg of BW and 75.4 ± 5.9 d of age) fed a diet unsupplemented with vitamin B(12) from weaning at 28 d of age were surgically equipped with catheters in the portal vein and carotid artery and an ultrasonic flow probe around the portal vein. Each pig received 3 boluses of 0 (B(12)-0), 25, and 250 μg of dietary vitamin B(12) according to a crossover design. Postprandial nycthemeral arterial plasma concentrations of vitamin B(12) reached minimum values (P < 0.01) between 15 and 18 h postmeal that were 29.6, 15.6, and 10.0% less than the premeal values for B(12)-0, B(12)-25, and B(12)-250 pigs, respectively (linear, P < 0.01). The cumulative net flux of vitamin B(12) for 24 h corresponded to 2.4 and 5.1 µg for B(12)-25 and B(12)-250 treatments, respectively, and the corresponding bioavailability was estimated to be 9.7 and 2.0%, respectively. Although bioavailability estimates varied according to approaches, both showed the inverse relationship between dietary vitamin B(12) and bioavailability of the vitamin. The dietary supplement of 25 µg was sufficient to maximize hepatic vitamin B(12) retention and to attenuate the nycthemeral decrease of arterial plasma concentration of the vitamin.

Methionine, folic acid and vitamin B12in growing-finishing pigs: Impact on growth performance and meat quality

“…Therefore, the most relevant meat enrichment for human nutrition purposes corresponded, in fact, to the small difference between V2 and V1 pigs. This marginal response between V2 and V1 pigs is consistent with the bioavailability of vitamin B 12 in growing-finishing pigs decreasing almost proportionally with the increased intake of dietary cyanocobalamin (Matte et al 2006).…”

Bioavailability of vitamin B12 in cows' milk

“…It cannot be ruled out that the present experimental approach based on the quantification of the net flux of vitamin B 12 through the PDV was not sensitive enough to detect the difference within this range of vitamin B 12 intakes ingested in one single supplemented meal. Such PDV flux values for vitamin B 12 were previously observed following ingestion of 250 mg of cyanocobalamin incorporated in a semi-purified diet containing vitamin-free casein (29) . Enhanced PDV flux of vitamin B 12 from milk could also be related to the forms of cobalamins present in milk.…”

“…supplements of cyanocobalamin has recently been studied (29) in this species using two different methods. A first one, used as a reference method, measured whole-body deposition of vitamin B 12 after several days of dietary supplementation, whereas the second method measured the net flux of vitamin B 12 across PDV following a single meal supplemented with cyanocobalamin.…”

Short communication: Casein hydrolysate and whey proteins as excipients for cyanocobalamin to increase intestinal absorption in the lactating dairy cow

“…Previous studies in pigs have estimated the bioavailability of dietary vitamin B 12 using portal-drained viscera (PDV) flux (Matte et al, 2010(Matte et al, , 2012.The cumulative net PDV fluxes of vitamin B 12 after ingestion of meals based on corn, wheat, and soybean meal and supplemented with 44 and 71 μg of CN-CBL were not different from 0 (Matte et al, 2012), suggesting no detectable absorption of vitamin B 12 . However, when CN-CBL was offered with a semi-synthetic diet consisting of vitamin-free casein hydrolysate, corn starch, and sucrose, the cumulative net PDV fluxes of vitamin B 12 during the 24 h following dietary boluses of 25 and 250 μg of CN-CBL were positive at 2.4 and 5.1 μg, respectively, and differed between doses (Matte et al, 2010). Therefore, combining a supplement of CN-CBL with specific milk proteins or peptides may be an approach to increase the amount of vitamin B 12 reaching portal blood.…”

“…Consequently, as portal-arterial difference and PDV flux estimated the amount of vitamin reaching the portal blood during a finite period, it could lead to underestimation of the amount of vitamin absorbed. In pigs, PDV flux of vitamin B 12 was positive when dietary CN-CBL was given with a semi-purified diet containing vitamin-free casein (Matte et al, 2010), but it was negative or not different from 0 when CN-CBL was given in a meal based on corn, wheat, and soybean meal (Matte et al, 2012). Indeed, in pig, PDV flux of vitamin B 12 was greater after ingestion of milk than the synthetic form of the vitamin, CN-CBL (Matte et al, 2012).…”