The folic acid and vitamin B12 content of the milk of various species

A Comprehensive Review of Bovine Colostrum Components and Selected Aspects Regarding Their Impact on Neonatal Calf Physiology

Colostrum contains macro- and micronutrients necessary to meet the nutritional and energy requirements of the neonatal calf, bioactive components that intervene in several physiological aspects, and cells and microorganisms that modulate the calf's immune system and gut microbiome. Colostrum is sometimes mistaken as transition milk, which, although more nutritive than whole milk, has a distinct biochemical composition. Furthermore, most research about colostrum quality and colostrum management focuses on the transfer of maternal IgG to the newborn calf. The remaining components of colostrum and transition milk have not received the same attention, despite their importance to the newborn animal. In this narrative review, a large body of literature on the components of bovine colostrum was reviewed. The variability of these components was summarized, emphasizing specific components that warrant deeper exploration. In addition, the effects of each component present in colostrum and transition milk on several key physiological aspects of the newborn calf are discussed.

Oral Administration as a Potential Alternative for the Delivery of Small Extracellular Vesicles

Small extracellular vesicles (sEVs) have burst into biomedicine as a natural therapeutic alternative for different diseases. Considered nanocarriers of biological origin, various studies have demonstrated the feasibility of their systemic administration, even with repeated doses. However, despite being the preferred route of physicians and patients, little is known about the clinical use of sEVs in oral administration. Different reports show that sEVs can resist the degradative conditions of the gastrointestinal tract after oral administration, accumulating regionally in the intestine, where they are absorbed for systemic biodistribution. Notably, observations demonstrate the efficacy of using sEVs as a nanocarrier system for a therapeutic payload to obtain a desired biological (therapeutic) effect. From another perspective, the information to date indicates that food-derived vesicles (FDVs) could be considered future nutraceutical agents since they contain or even overexpress different nutritional compounds of the foods from which they are derived, with potential effects on human health. In this review, we present and critically analyze the current information on the pharmacokinetics and safety profile of sEVs when administered orally. We also address the molecular and cellular mechanisms that promote intestinal absorption and that command the therapeutic effects that have been observed. Finally, we analyze the potential nutraceutical impact that FDVs would have on human health and how their oral use could be an emerging strategy to balance nutrition in people.

Chemical Composition of Commercial Cow's Milk

Bovine milk is a nutritionally rich, chemically complex biofluid consisting of hundreds of different components. While the chemical composition of cow's milk has been studied for decades, much of this information is fragmentary and very dated. In an effort to consolidate and update this information, we have applied modern, quantitative metabolomics techniques along with computer-aided literature mining to obtain the most comprehensive and up-to-date characterization of the chemical constituents in commercial cow's milk. Using nuclear magnetic resonance (NMR) spectroscopy, liquid chromatography-mass spectrometry (LC-MS), and inductively coupled plasma-mass spectrometry (ICP-MS), we were able to identify and quantify 296 bovine milk metabolites or metabolite species (corresponding to 1447 unique structures) from a variety of commercial milk samples. Through our literature analysis, we also found another 676 metabolites or metabolite species (corresponding to 908 unique structures). Detailed information regarding all 2355 of the identified chemicals in bovine milk have been made freely available through a Web-accessible database called the Milk Composition Database or MCDB ( http://www.mcdb.ca/ ).

A 100-Year Review: Advances in goat milk research

In the century of research chronicled between 1917 and 2017, dairy goats have gone from simply serving as surrogates to cows to serving as transgenic carriers of human enzymes. Goat milk has been an important part of human nutrition for millennia, in part because of the greater similarity of goat milk to human milk, softer curd formation, higher proportion of small milk fat globules, and different allergenic properties compared with cow milk; however, key nutritional deficiencies limit its suitability for infants. Great attention has been given not only to protein differences between goat and cow milk, but also to fat and enzyme differences, and their effect on the physical and sensory properties of goat milk and milk products. Physiological differences between the species necessitate different techniques for analysis of somatic cell counts, which are naturally higher in goat milk. The high value of goat milk throughout the world has generated a need for a variety of techniques to detect adulteration of goat milk products with cow milk. Advances in all of these areas have been largely documented in the Journal of Dairy Science (JDS), and this review summarizes such advances.

Short communication: Factors affecting vitamin B12 concentration in milk of commercial dairy herds: An exploratory study

Only bacteria can synthesize vitamin B12, and this requires adequate Co supply. The natural source of vitamin B12 in human diets comes from animal products, especially those from ruminants. This study aimed to describe variability regarding vitamin B12 concentration in milk among and within commercial dairy herds in early lactation. A secondary objective was to explore potential causes for this variability such as genetic variation and diet characteristics. In total, 399 dairy cows (135 primiparous and 264 multiparous; 386 Holstein and 13 Jersey cows) in 15 commercial herds were involved. Milk samples were taken at 27.4±4.1 and 55.4±4.1d in milk. Neither parity (primiparous vs. multiparous) nor sampling time affected milk concentrations of vitamin B12. Nevertheless, vitamin B12 concentration in milk was highly variable among and within dairy herds. The lowest vitamin B12 concentration in milk of cows was observed in the Jersey herd. Among herds, vitamin B12 concentration in milk ranged from 2,309 to 3,878 pg/mL; one glass (250mL) of milk from those herds would provide between 23 and 40% of the vitamin B12 recommended daily allowance. Among individual cows, however, this provision varied between 16 and 57% of the recommendation. In spite of the limited size of the studied population, the heritability value was 0.23, suggesting that genetic selection could modify milk vitamin B12 concentration. We observed a positive relationship between milk vitamin B12 concentration and dietary acid detergent fiber content and a negative relationship between milk concentration of vitamin B12 and dietary crude protein content.

Temporal folate status during lactation in mares and growth in foals

OBJECTIVE

To identify changes in folate status of mares and foals during lactation and growth, respectively.

ANIMALS

20 Thoroughbred mares and foals.

PROCEDURES

Pregnant mares, and following foaling the same mares with their foals, were maintained on mixed grass-legume pasture and fed either a traditional dietary supplement rich in sugar and starch (SS) or a dietary supplement high in fat and fiber (FF). Blood samples were collected monthly from mares and foals up to 6 months after foaling. Total folate concentration in feed and forage was determined. Analyses of plasma folate, RBC folate, plasma homocysteine (HCY), and milk folate concentrations were performed.

RESULTS

Mare plasma folate concentrations declined moderately during 6 months of lactation. Mare RBC folate concentrations initially increased after foaling up to 3 months but declined toward the end of the study. Plasma HCY concentration was higher for mares fed the SS supplement, compared with mares fed the FF supplement from foaling to 6 months of lactation. Milk folate concentrations decreased during the first 3 months and then increased. Foal plasma folate initially declined but then increased. Stable concentrations of RBC folate were observed in foals. Plasma HCY concentrations in foals were unaffected by growth during the last 5 months. References range values for plasma folate, RBC folate, milk folate, and plasma HCY concentrations in healthy lactational mares and young growing foals were determined.

CONCLUSIONS AND CLINICAL RELEVANCE

Folate status was not impaired in lactating mares and growing foals under the conditions in our study. It appears that folate supplementation is not necessary.

Nutritional vitamin B12 deficiency in a breastfed infant following maternal gastric bypass

Breastfed infants of women who have had gastric or intestinal bypass procedures may develop nutritional deficiencies. We describe a 10-month-old exclusively breastfed white male infant who presented with vomiting, failure to thrive, and megaloblastic anemia. He was found to have vitamin B12 deficiency. His mother had undergone a gastric bypass procedure for morbid obesity 2 years prior to her pregnancy with this child. She had subclinical vitamin B12 deficiency, with an abnormal Schilling test that corrected with the addition of intrinsic factor. Therefore, we believe that the mother's gastric bypass had caused a decrease in available intrinsic factor, resulting in subclinical vitamin B12 deficiency and decreased breast milk B12. Although she was asymptomatic, her breastfed infant developed symptomatic B12 deficiency. This is the first reported case of a maternal gastric bypass resulting in vitamin B12 deficiency in an infant. These mothers should receive vitamin supplements, including vitamin B12, during and after pregnancy, and may require parenterally administered vitamin B12.

Vitamin B12 in human colostrum and milk. Quantitation of the vitamin and its binder and the uptake of bound vitamin B12 by intestinal bacteria

The concentration of vitamin B12 was measured by microbiological assay in 229 samples of normal human colostrum and milk taken at various stages of lactation. Colostrum obtained within 48 hours of delivery contains high concentrations of vitamin B12 (mean 2 431 pg/ml), but within a few days the levels fall to a range similar to the levels in normal serum. The vitamin B12 binding capacity of 111 samples of colostrum and milk was estimated by gel filtration or charcoal binding. Colostrum samples have a mean binding capacity of 72 ng/ml, while the binding capacity in milk is only one third of this value. The ability of a range of intestinal bacteria to take up colostrum-bound vitamin B12, was assessed. All the organisms took up free vitamin B12, but when the vitamin was bound in colostrum, there was little or no uptake even after 24 hours incubation.

Maternal milk and serum vitamin B12, folic acid, and protein levels in Indian subjects

Serum vitamin B12 and folic acid activity levels were studied in 47 mothers. The mean serum vitamin B12 value in non-vegetarian mothers was 228 μμg./ml. ± 38·9 SE, as compared to mean values 97 μμg./ml. ± 20·7 SE in lacto-vegetarians. There was no significant difference in folic acid levels, haemoglobin, and total proteins among the different dietetic groups. Analysis of milk revealed mean vitamin B12 values of 103 μμg./ml. in non-vegetarians as compared to 91 μμg./ml. in lacto-vegetarians; the difference was not statistically significant. Mean total protein and folic acid levels for milk were similar in different dietetic groups. The figures obtained for vitamin B12 content of human milk in these mothers are considerably lower than those reported in similar studies from Western countries.