Exploring Vitamin B12 Supplementation in the Vegan Population: A Scoping Review of the Evidence.

With a significant portion of the population adopting veganism and conflicting views among nutrition professionals regarding the necessity of vitamin B12 supplementation, this review aims to explore existing studies evaluating interventions through food supplementation. It focuses on the impact of vitamin B12 deficiency across different demographics. The present study seeks to understand how research has addressed the relationship between the rise in veganism and vitamin B12 deficiency over the past decade. A scoping review was conducted following the PRISMA flow diagram. Studies from 2010 to 2023 were identified using Boolean operators and key terms in electronic databases such as PubMed/MEDLINE, Web of Science, and EBSCO (Library, Information Science & Technology Abstracts, and Academic Search Complete). Out of 217 articles identified, 70 studies were included. The topical analysis categorized the studies into three groups: those associating vitamin B12 deficiency with diseases (n = 14), those analyzing the dietary habits of vegetarian individuals (vegan or not) without a specific focus on vitamin B12 (n = 49), and those addressing food guides and nutrition institution positions (n = 7). The authors concluded that vitamin B12 deficiency is prevalent among vegans due to limited consumption of animal products. For vegetarians, supplementation is an efficient means of treating and preventing deficiency; a daily dose of 50 to 100 micrograms is advised. There are still significant gaps in the research, nevertheless, such as the absence of randomized controlled trials evaluating various forms or dosages of vitamin B12 among vegetarians and the requirement for more information and awareness of the vitamin's significance in vegan diets.

Expression of genes for Kisspeptin (KISS1), Neurokinin B (TAC3), Prodynorphin (PDYN), and gonadotropin inhibitory hormone (RFRP) across natural puberty in ewes.

Expression of particular genes in hypothami of ewes was measured across the natural pubertal transition by in situ hybridization. The ewes were allocated to three groups (n = 4); prepubertal, postpubertal and postpubertally gonadectomized (GDX). Prepubertal sheep were euthanized at 20 weeks of age and postpubertal animals at 32 weeks. GDX sheep were also euthanized at 32 weeks, 1 week after surgery. Expression of KISS1, TAC3, PDYN in the arcuate nucleus (ARC), RFRP in the dorsomedial hypothalamus and GNRH1 in the preoptic area was quantified on a cellular basis. KISS1R expression by GNRH1 cells was quantified by double-label in situ hybridization. Across puberty, detectable KISS1 cell number increased in the caudal ARC and whilst PDYN cell numbers were low, numbers increased in the rostral ARC. TAC3 expression did not change but RFRP expression/cell was reduced across puberty. There was no change across puberty in the number of GNRH1 cells that expressed the kisspeptin receptor (KISS1R). GDX shortly after puberty did not increase expression of any of the genes of interest. We conclude that KISS1 expression in the ARC increases during puberty in ewes and this may be a causative factor in the pubertal activation of the reproductive axis. A reduction in expression of RFRP may be a factor in the onset of puberty, removing negative tone on GNRH1 cells. The lack of changes in expression of genes following GDX suggest that the effects of gonadal hormones may differ in young and mature animals.

Educação para a Saúde Familiar ­ Perceção dos Enfermeiros / Family Health Education - Nurses' Perceptions

A educação para a saúde (EpS) familiar na prática clínica de enfermagem capacita a família para promover a saúde familiar. Este estudo teve por objetivo identificar o quorum de boas práticas de EpS dos enfermeiros focadas na família e verificar qual a perceção que os enfermeiros têm em relação a essas boas práticas. A partir da análise do artigo "Educação em Saúde na Estratégia de Saúde da Família: percepção dos profissionais" de Silva, Lemos e Hardman (2015) e de uma revisão da literatura, identificaram-se cinco fatores, que foram posteriormente validados e hierarquizados segundo peso/importancia por peritos em enfermagem das várias áreas de especialização, num Painel Delphi online. O estudo realizado é transversal descritivo ­ correlacionado. A amostra foi constituída por 272 enfermeiros que realizam EpS familiar em Portugal, a partir do total dos enfermeiros que exercem em Portugal, 73650. Com os dados do questionário aplicado construíu-se e validou-se a Escala Educação para a Saúde Familiar ­ Perceção dos Enfermeiros (ESfamília).Ficando esta constituída por dois fatores (a promoção da saúde familiar através da EpS e a EpS familiar não normativa), que resultam da Análise Fatorial e explicam 68,66% da variância total. A consistência interna da escala, avaliada pelo Alfa de Chronbach, revelou-se muito boa (0,974). Dos resultados destaca-se que a ESfamília, ficou constituída por dois fatores sendo que os enfermeiros atribuíram maior importância ao fator a EpS familiar não normativa (M=4,56; Dp±0,54) e um pouco menor importância à Promoção da saúde familiar através da EpS (M=4,41; Dp±0,54). Os resultados indiciam que a EpS familiar pode ser realizada em qualquer contexto, sendo que os contextos em que a EpS familiar é mais realizada é no centro de saúde e no domicílio. Conclui-se que os enfermeiros atribuíram grande importância aos fatores e à ESfamília, realçando que a EpS familiar em enfermagem deve ser não normativa para capacitar as famílias para promoverem a sua saúde.

Education for family health in clinical nursing practice enables the family to promote family health. This study aimed to identify the quorum good health education practices focused in family nursing and verify the perception that nurses have regarding these good practices. From the analysis of the article "Health Education in the Family Health Strategy: perceptions of professionals" Silva, Lemos and Hardman (2015) and a literature review, we identified five factors, that were later validated and ranked second weight / importance of experts in nursing from various areas of expertise on Delphi Panel online. We developed a cross sectional study, through the use of questionnaires built for this purpose to a random sample of 272 nurses working in Portugal and conduct education for family health, from a total of 73650 nurses working in Portugal. With the questionnaire data applied was constructed and validated to Scale Education for Family Health - Perception of Nurses (ESfamília). It was composed of two factors (the promotion of family health through health education and education for family health nonnormative), that appeared in Factorial Analysis of the results and explains 68.66% of the total variance. Consistency Internal scale, as assessed by Alfa de Chronbach, proved to be very good (0.974). From the results highlight in the ESfamília, that was composed of two factors, the nurses gave greater importance to the factor education for family health non-normative (M=4,56; Dp±0,54) and less importance to the promotion of family health through health education (M=4,41; Dp±0,54). The results indicate that education for family health can be performed in any context, and the contexts in which education for family health is most accomplished is in the health center and at home. We conclude that nurses gave great importance to the factors and ESfamília, furthermore the nursing family education should be non normative to empower families to their own healthcare.

Kisspeptin is a component of the pulse generator for GnRH secretion in female sheep but not the pulse generator.

We tested the hypothesis that kisspeptin cells constitute the "pulse generator" for GnRH secretion. In ewes, we determined whether iv administered kisspeptin elicits a secretory pulse of LH in anaesthetized, sex-steroid suppressed ovariectomized ewes. A response was seen in both anaesthetized and conscious animals, which was not associated with induction of c-Fos labeling in GnRH cells, supporting the notion that kisspeptin acts on the neurosecretory GnRH terminals. Response was lower in the anaesthetized animals, suggesting that some nonkisspeptin elements may be involved in GnRH responses. Microinjection of kisspeptin (100 nmol) into the median eminence of conscious ewes elicited a pulse of LH, indicating that kisspeptin acts at this level to cause GnRH secretion. To determine which cells are activated at the time of GnRH secretion, we blood sampled 18 ewes during the luteal phase of the estrous cycle and harvested brains after 3 hours. Three of these ewes displayed a pulse of LH within 30 minutes of euthanasia. An increase in c-Fos labeling was seen in kisspeptin and glutamate cells of the arcuate nucleus but not in GnRH neurons, preoptic kisspeptin neurons, or preoptic glutamate neurons. Immunohistochemistry in 4 hypothalami showed that 72% of arcuate kisspeptin cells receive glutamatergic input. These data support the concept that the kisspeptin cells of the arcuate nucleus drive pulsatile secretion of GnRH at the level of the median eminence, but this may involve "upstream" input from glutamate cells. We conclude that the pulse generator for GnRH secretion involves more than 1 element.

Hypothalamic expression of KISS1 and gonadotropin inhibitory hormone genes during the menstrual cycle of a non-human primate.

Kisspeptin, the product of the KISS1 gene, stimulates gonadotropin-releasing hormone (GnRH) secretion; gonadotropin inhibitory hormone (GnIH), encoded by the RF-amide-related peptide (RFRP) or NPVF gene, inhibits the reproductive axis. In sheep, kisspeptin neurons are found in the lateral preoptic area (POA) and the arcuate nucleus (ARC) and may be important for initiating the preovulatory GnRH/luteinizing hormone (LH) surge. GnIH cells are located in the ovine dorsomedial hypothalamic nucleus (DMN) and paraventricular nucleus (PVN), with similar distribution in the primate. KISS1 cells are found in the primate POA and ARC, but the function that kisspeptin and GnIH play in primates has not been elucidated. We examined KISS1 and NPVF mRNA throughout the menstrual cycle of a female primate, rhesus macaque (Macaca mulatta), using in situ hybridization. KISS1-expressing cells were found in the POA and ARC, and NPVF-expressing cells were located in the PVN/DMN. KISS1 expression in the caudal ARC and POA was higher in the late follicular phase of the cycle (just before the GnRH/LH surge) than in the luteal phase. NPVF expression was also higher in the late follicular phase. We ascertained whether kisspeptin and/or GnIH cells project to GnRH neurons in the primate. Close appositions of kisspeptin and GnIH fibers were found on GnRH neurons, with no change across the menstrual cycle. These data suggest a role for kisspeptin in the stimulation of GnRH cells before the preovulatory GnRH/LH surge in non-human primates. The role of GnIH is less clear, with paradoxical up-regulation of gene expression in the late follicular phase of the menstrual cycle.

Kisspeptin cells in the ewe brain respond to leptin and communicate with neuropeptide Y and proopiomelanocortin cells.

Kisspeptin stimulates reproduction, and kisspeptin cells in the arcuate nucleus (ARC) express Ob-Rb in the mouse. Herein we report studies in ewes to determine whether kisspeptin cells express Ob-Rb and respond to leptin and whether reciprocal connections exist between kisspeptin cells and proopiomelanocortin (POMC) or neuropeptide Y (NPY) cells to modulate reproduction and metabolic function. Kiss1 mRNA was measured by in situ hybridization in ovariectomized ewes that were normal body weight, lean, or lean with leptin treatment by intracerebroventricular (icv) infusion (4 microg/h, 3 d). Kiss1 expression in the ARC and the preoptic area was lower in hypogonadotropic lean animals than animals of normal weight, and icv infusion of leptin partially restored Kiss1 expression in lean animals. Single-cell laser capture microdissection coupled with real-time PCR showed that Kiss1 cells in the preoptic area and ARC express Ob-Rb. Double-label fluorescent immunohistochemistry showed that reciprocal connections exist between kisspeptin cells and NPY and POMC cells. Accordingly, we treated ovariectomized ewes with kisspeptin (5 microg/h, icv) or vehicle for 20 h and examined POMC and NPY gene expression by in situ hybridization. Kisspeptin treatment reduced POMC and increased NPY gene expression. Thus, kisspeptin neurons respond to leptin and expression of Kiss1 mRNA is affected by leptin status. Kisspeptin cells communicate with NPY and POMC cells, altering expression of the relevant genes in the target cells; reciprocal connections also exist. This network between the three cell types could coordinate brain control of reproduction and metabolic homeostatic systems.

Expression of genes for appetite-regulating peptides in the hypothalamus of genetically selected lean and fat sheep.

BACKGROUND/AIMS: The aim was to determine whether genetic selection of sheep for body composition could be accounted for by changes in the level of expression of genes for appetite-regulating peptides in the hypothalamus. We examined gene expression in the hypothalamus of genetically lean, normal and fat ewes (n = 5/group). METHODS: Plasma growth hormone (GH) and metabolic indicators were measured and gene expression in brains was quantified by in situ hybridization. RESULTS: Body weight and voluntary food intake (VFI) were similar between groups, but lean and fat animals respectively had low and high indices of adiposity. GH levels were higher in lean and fat animals than in controls. In the arcuate nucleus (ARC), neuropeptide Y (NPY) expression/cell was higher in the lean animals than in normal animals, but overall NPY expression was similar in fat and normal animals. Pro-opiomelanocortin (POMC) and leptin receptor (ObRb) expression in the ARC was similar across groups. Orexin (ORX) and melanin-concentrating hormone (MCH) expression was inversely correlated to adiposity, being higher in lean and lower in fat animals. CONCLUSION: Expression of genes for orexigenic neuropeptides is altered in a consistent way. Energy expenditure is reduced by MCH but increased by ORX, so increased expression of the latter may cause increased energy expenditure in the lean animals and vice versa in the fat animals.

Kisspeptin neurons in the arcuate nucleus of the ewe express both dynorphin A and neurokinin B.

Kisspeptin is a potent stimulator of GnRH secretion that has been implicated in the feedback actions of ovarian steroids. In ewes, the majority of hypothalamic kisspeptin neurons are found in the arcuate nucleus (ARC), with a smaller population located in the preoptic area. Most arcuate kisspeptin neurons express estrogen receptor-alpha, as do a set of arcuate neurons that contain both dynorphin and neurokinin B (NKB), suggesting that all three neuropeptides are colocalized in the same cells. In this study we tested this hypothesis using dual immunocytochemistry and also determined if kisspeptin neurons contain MSH or agouti-related peptide. To assess colocalization of kisspeptin and dynorphin, we used paraformaldehyde-fixed tissue from estrogen-treated ovariectomized ewes in the breeding season (n = 5). Almost all ARC, but no preoptic area, kisspeptin neurons contained dynorphin. Similarly, almost all ARC dynorphin neurons contained kisspeptin. In experiment 2 we examined colocalization of kisspeptin and NKB in picric-acid fixed tissue collected from ovary intact ewes (n = 9). Over three quarters of ARC kisspeptin neurons also expressed NKB, and a similar percentage of NKB neurons contained kisspeptin. In contrast, no kisspeptin neurons stained for MSH or agouti-related peptide. These data demonstrate that, in the ewe, a high percentage of ARC kisspeptin neurons also produce dynorphin and NKB, and we propose that a single subpopulation of ARC neurons contains all three neuropeptides. Because virtually all of these neurons express estrogen and progesterone re-ceptors, they are likely to relay the feedback effects of these steroids to GnRH neurons to regulate reproductive function.

The role of noradrenaline in the generation of the preovulatory LH surge in the ewe.

Increasing plasma estrogen (E) levels during the follicular phase of the estrous cycle trigger the pre-ovulatory surge of gonadotropin-releasing hormone (GnRH)/LH. Noradrenaline (NA)-producing cells of the brain stem are involved in regulating GnRH cells and project to the preoptic area (POA) and bed nucleus of stria terminalis (BnST). Input to GnRH cells may be direct or indirect, via relay neurons in the POA/BnST. To investigate this, we ascertained whether an alpha(1)-adrenergic antagonist would block/delay the LH surge in ovariectomised (OVX), E-treated ewes. E benzoate (EB) (50microg) was injected (i.m.) and Doxazosin (100nmol/h) or vehicle was infused into the third ventricle 2-26h after EB injection. Doxazosin reduced the magnitude of the LH surge, but did not affect timing. To determine if NA is released in the POA/BnST of cyclic ewes, we immunostained dopamine-beta-hydroxylase (DBH) in terminal fields. Reduced numbers of varicosities staining for DBH indicates release of NA. The number of varicosities immunostained for DBH was reduced in the dorsal and lateral BnST during the follicular phase and during the preovulatory LH surge compared to the luteal phase. These data suggest that noradrenergic mechanisms are involved in generation of the GnRH/LH surge via projections to the BnST and relay to GnRH cells. Since Doxasozin reduced the magnitude of the LH surge in the E-treated OVX ewe, and release of NA in cyclic ewes occurred during the follicular phase of the estrous cycle, we speculate that NA is a permissive factor in surge generation. Thus, increased noradrenergic activity is not a trigger mechanism for initiation of the surge.

Effects of changing gonadotropin-releasing hormone pulse frequency and estrogen treatment on levels of estradiol receptor-alpha and induction of Fos and phosphorylated cyclic adenosine monophosphate response element binding protein in pituitary gonadotropes: studies in hypothalamo-pituitary disconnected ewes.

Estrogen receptor-alpha (ER alpha) levels in gonadotropes are increased during the follicular phase of the ovine estrous cycle, a time of increased frequency of pulsatile secretion of GnRH and elevated plasma estrogen levels. In the present study, our first aim was to determine which of these factors causes the rise in the number of gonadotropes with ER alpha. Ovariectomized hypothalamo-pituitary disconnected ewes (n = 4-6) received the following treatments: 1) no treatment, 2) injection (im) of 50 microg estradiol benzoate (EB), 3) pulses (300 ng iv) of GnRH every 3 h, 4) GnRH treatment as in group 3 and EB treatment as in group 2, 5) increased frequency of GnRH pulses commencing 20 h before termination, and 6) GnRH treatment as in group 5 with EB treatment. These treatments had predictable effects on plasma LH levels. The number of gonadotropes in which ER alpha was present (by immunohistochemistry) was increased by either GnRH treatment or EB injection, but combined treatment had the greatest effect. Immunohistochemistry was also performed to detect phosphorylated cAMP response element binding protein (pCREB) and Fos protein in gonadotropes. The number of gonadotropes with Fos and with pCREB was increased only in group 6. We conclude that either estrogen or GnRH can up-regulate ER alpha in pituitary gonadotropes. On the other hand, during the period of positive feedback action of estrogen, the appearance of pCREB and Fos in gonadotropes requires the combined action of estrogen and increased frequency of GnRH input. This suggests convergence of signaling for GnRH and estrogen.

Evidence for estrogenic regulation of gonadotropin-releasing hormone neurons by glutamatergic neurons in the ewe brain: An immunohistochemical study using an antibody against vesicular glutamate transporter-2.

Gonadotropin-releasing hormone (GnRH) secretion is controlled by various factors, including the excitatory neurotransmitter glutamate. Estrogen (E) regulates GnRH secretion by means of E-responsive cells in the brain that relay the feedback effects to the preoptic area (POA). We used an antibody to vesicular glutamate transporter 2 (VGluT2) to label glutamatergic neurons in the areas of the ewe brain that control GnRH secretion. VGluT2-immunoreactive cells were observed in the arcuate nucleus (ARC)/ventromedial hypothalamic nucleus (VMH) complex, POA, bed nucleus of stria terminalis (BnST), and A1 and A2 cell groups in the brainstem. In three ewes, E receptor-alpha was detected in 52-61% of glutamatergic neurons in ARC/VMH, 37-52% of neurons in the POA, and 37-58% of neurons in the BnST. E injection (i.m. or i.v.) increased the percentage of glutamatergic cells that expressed Fos protein in the ARC (P < 0.01 and P < 0.001, respectively). In six ewes, injection of the retrograde tracer Fluoro-Gold into the POA labeled cells in the ARC and 6-29% of these were also VGluT2-immunoreactive. Double-labeling of varicosities in the POA showed colocalization of VGluT2 in 12.5 +/- 3% of dopamine beta-hydroxylase-immunoreactive terminals, indicating that a subset of glutamatergic inputs could arise from brainstem noradrenergic neurons cells. In the POA, 60% of GnRH neurons had close appositions that were VGluT2-immunoreactive. We conclude that E-responsive glutamatergic neurons arising from the brainstem, the BnST, and ARC/VMH provide input to the POA and may be involved in the regulation of GnRH secretion.