Dietary Vitamin D3 Supplementation Research Articles

Effects of Long-Term Dietary High Vitamin D3 Supplementation on Cognition, the Brain Transcriptome and Microbiome in Male and Female Aging F344 Rats

Effects of Long-Term Dietary High Vitamin D3 Supplementation on Cognition, the Brain Transcriptome and Microbiome in Male and Female Aging F344 Rats

Dietary Super-Doses of Cholecalciferol Fed to Aged Laying Hens Illustrates Limitation of 24,25-Dihydroxycholecalciferol Conversion

BackgroundOlder humans taking high concentrations of vitamin D3 supplementation for a prolonged time may be at risk of vitamin D toxicity. It is unclear how dietary super-doses (10,000 times greater than the requirement) can affect vitamin D3 status in aged animals. Aged laying hens could be a model to compare vitamin D3 supplementation effects with women in peri- or postmenopausal stages of life. ObjectivesWe investigated the dietary super-dose impacts of cholecalciferol (vitamin D3) on vitamin D3 status in aged laying hens in production. MethodsForty-eight 68-wk-old Hy-Line Brown laying hens were individually housed in cages with 8 hens per dietary treatment for 11 wk. Hens were randomly assigned to 1 of 6 treatment groups of dietary vitamin D3 supplementation and consumed ad libitum. Supplementation concentrations were 400, 800, 7400, 14,000, 20,000, and 36,000 IU D3/kg of feed. At the end of the study, all hens were sacrificed, and tissue samples and feces were collected. Plasma and egg yolk vitamin D3 metabolites, calcium and phosphorus composition of eggshells, ileal digesta, and feces were measured. Duodenal, ileal, liver, and kidney gene expression levels were also measured. ResultsWe observed that increasing dietary vitamin D3 increased plasma vitamin D3 and egg yolk vitamin D3 (P < 0.0001 for both sites). We also observed an increase in plasma 24,25-dihydroxycholecalciferol as dietary vitamin D3 concentrations increased (P < 0.0001). The plasma 25-hydroxycholecalciferol:24,25-dihydroxycholecalciferol ratio exhibited an asymptotic relationship starting at the 14,000 IU/kg D3 treatment. ConclusionsDietary super-doses of vitamin D3 led to greater plasma and egg yolk vitamin D3 concentrations, which shows that aged laying hens can deposit excess vitamin D3 in egg yolk. We suggest future research should explore how 24-hydroxylation mechanisms are affected by vitamin D3 supplementation. Further understanding of 24-hydroxylation can help ascertain ways to reduce the risk of vitamin D toxicity.

The Effects of Optimal Dietary Vitamin D3 on Growth and Carcass Performance, Tibia Traits, Meat Quality, and Intestinal Morphology of Chinese Yellow-Feathered Broiler Chickens.

This study aimed to assess the effects of different dietary vitamin D3 (VD3) levels on growth and carcass performance, tibia traits, meat quality, and intestinal morphology of yellow-feathered broilers. One-day-old broilers (n = 1440) were assigned into four treatment groups with six replicates per group, and each replicate contained 60 chicks. Dietary VD3 significantly improved the growth performance and carcass traits of broilers, and only low-dose VD3 supplementation decreased the abdominal fat percentage. High-dose VD3 supplementation improved intestinal morphology in the finisher stage, while the b* value of breast muscle meat color decreased markedly under VD3 supplementation (p < 0.05). Serum Ca and P levels and the tibia composition correlated positively with dietary VD3 supplementation at the early growth stage. The weight, length, and ash contents of the tibia increased linearly with increasing dietary VD3, with maximum values achieved in the high-dose group at all three stages. Intestinal 16S rRNA sequencing and liver transcriptome analysis showed that dietary VD3 might represent an effective treatment in poultry production by regulating lipid and immune-related metabolism in the gut-liver axis, which promotes the metabolism through the absorption of calcium and phosphorus in the intestine and improves their protective humoral immunity and reduces infection mortality. Dietary VD3 positively affected the growth-immunity and bone development of broilers during the early stage, suggesting strategies to optimize poultry feeding.

Effects of Dietary Vitamin D3 Over-Supplementation on Broiler Chickens' Health; Clinicopathological and Immunohistochemical Characteristics

Introduction: Vitamin D3 is used as a supplement in the feeds of livestock, pets, and human infants. However, the presence of excessive Vitamin D3 has been shown to cause toxicity in humans and animals. This study investigated the clinicopathological aspects of Vitamin D3 toxicity in broiler chickens. Materials and methods: The median lethal dose (LD50) of Vitamin D3 was estimated by the up-and-down method. To determine long term (21 days) toxic effects of oral Vitamin D3 supplementation, 90 (14-day-old) IBL-80 unsexed chicks were randomly divided into three groups as group A (control, received basal diet), B (basal diet + Vitamin D3 at 16.67 mg/kg body weight daily), and C (basal diet + Vitamin D3 at 33.33 mg/kg body weight daily). Results: The findings indicated that broiler chickens tolerated a single oral dose of Vitamin D3 up to 550 mg/kg body weight (22,000,000 IU/kg) without mortality. The results of long-term (21 days) oral supplementation of divided doses of Vitamin D3 in broiler chickens (groups B and C) showed progressive emaciation, elevated hemoglobin, hypercalcemia, hypophosphatemia, and increased alkaline phosphatase activity. At necropsy, pale liver and kidneys, congestion and hardening of lungs, mild congestion in the brain, and soft bones were observed in Vitamin D3 treated chicks (groups B and C). Microscopically, degeneration and metastatic calcification in lung parenchyma and peribronchiolar epithelium, coagulative necrosis and calcification in kidneys, and calcification with fibroplasia in proventriculus was detected. Lungs and kidneys showed a significant difference in calcification score between groups B and C. Broiler chickens from Vitamin D3 treated groups (B and C) showed strong immunohistochemical expression of Calbindin D28K in the intestine and kidneys but weak expression in the lungs. Conclusion: This study demonstrates that broiler chicks can tolerate very high levels of a single oral dose of Vitamin D3. Toxic effects of prolonged exposure to Vitamin D3 are due to over-expression of Calbindin D28k in the intestine and kidneys, disturbing the calcium and phosphorous homeostasis and leading to metastatic calcification of vital organs. This study supports that prolonged over-supplementation of Vitamin D3 causes toxic effects; hence, appropriate dietary Vitamin D3 supplementation limits should be set.

Long term dietary vitamin D3 supplementation impacts both microbicidal and inflammatory responses to ex-vivo Mycobacterium bovis BCG challenge in dairy calves

Vitamin D deficiency (VDD) is associated with enhanced susceptibility to multiple respiratory diseases in humans, including tuberculosis. However, the consequences of VDD for disease susceptibility in calves are unknown. Previously we developed a model to drive divergent circulating 25OHD concentrations in cattle, where animals were supplemented with vitamin D3 (vit D3) from birth to 7 months of age. Calves in the control group (Ctl) received a diet containing a standard vit D3 concentration, whereas the vit D group (VitD) received a diet with the highest vit D3 concentration allowed under EU guidelines. Here, we assessed the microbicidal activity and immunoregulatory effect of divergent 25OHD circulating levels to Mycobacterium bovis BCG challenge ex-vivo. Blood samples from Ctl and VitD calves were taken at 1-, 3- and 7-months of age. 25OHD concentrations were significantly different at 7 months (but not at 1 or 3 months) with animals from the VitD group having higher serum levels. Differences in microbicidal activity followed the same pattern, with no significant differences observed at 1 and 3 months, but at 7 months a significant increase in the percentage of bacteria killed was detected. Furthermore, analysis of the reactive oxygen species (ROS) and nitric oxide (NO) in serum showed a higher production of ROS and NO in VitD-supplemented calves. In contrast, serum concentrations of IL-1β and IL-8 were significantly lower. A similar anti-inflammatory profile was observed after gene expression analysis, with a significant downregulation of a cluster of genes including IL1B, IL1R1, CXCL1, CXCL2, CXCL5, MMP9 and COX2 and an upregulation of CXCR1, CX3CR1 and NCF1, in VitD calves after BCG challenge relative to Ctl animals. Collectively, these results suggest that dietary vit D3 boosts antimicrobial and innate immune responses and thereby could improve host anti-mycobacterial immunity.

Decreased growth differentiation factor 9, bone morphogenetic protein 15, and forkhead box O3a expressions in the ovary via ulipristal acetate.

Folliculogenesis is a complex process involving various ovarian paracrine factors. During folliculogenesis, vitamin D3 and progesterone are significant for the proper development of follicles. This study aimed to investigate the effects of vitamin D3 and selective progesterone receptor modulator ulipristal acetate on ovarian paracrine factors. In the study, 18 female Wistar-albino rats were randomly divided into three groups: control group (saline administration, n=6), vitamin D3 group (300 ng/day vitamin D3 oral administration, n=6), and UPA group (3 mg/kg/day ulipristal acetate oral administration, n=6). Ovarian tissue was analyzed by histochemistry and immunohistochemistry. For quantification of immunohistochemistry, the mean intensities of growth differentiation factor 9, bone morphogenetic protein 15, and forkhead box O3a expressions were measured by Image J and MATLAB. Blood samples were collected for the analysis of serum anti-Müllerian hormone levels by ELISA. Atretic follicles and hemorrhagic cystic structures were observed in the UPA group. After immunohistochemistry via folliculogenesis assessment markers, growth differentiation factor 9, bone morphogenetic protein 15, and cytoplasmic forkhead box O3a expressions decreased in the UPA group (p<0.05). Anti-Müllerian hormone level did not differ significantly between the experimental groups (p>0.05). Ulipristal acetate negatively affects folliculogenesis via ovarian paracrine factors. The recommended dietary vitamin D3 supplementation in healthy cases did not cause a significant change.

Requirements and Metabolism for Calcium, Phosphorus and Vitamin D3 in the Growing-Furring Blue Foxes.

Simple SummaryThe nutritional needs of mink and foxes have long been clear, not specifically for blue foxes. With the development of technology, the present study aimed to study the effect of dietary calcium, phosphorus, and vitamin D3 supplementation levels on the growth performance, nutrient digestibility, and serum biochemical indicators of the growing hairy blue fox. The results showed that Ca (0.8–1.2%) and vitamin D3 (1327 IU·kg−1) doses have important effects on the growth performance and nutrient digestibility of growing blue foxes and can reduce fecal nitrogen and fecal phosphorus by improving the utilization of protein and phosphorus.A 3 × 3 factorial experiment was conducted to investigate the influence of dietary calcium, phosphorus, and vitamin D3 (VD3) supplement levels on the growth performance, nutrient digestibility, and serum biochemical indices of growing-furring blue foxes. One hundred and thirty-five 120-day-old male blue foxes were randomly allocated into nine groups. The nine treatment diets were supplemented with 0%, 0.4%, or 0.8% Ca, and 1000, 2000, or 4000 IU·kg−1 VD3. The base diet contained 0.8% Ca and 327 IU·kg−1 VD3. The dietary calcium level had a significant effect on the average daily gain (ADG) of blue foxes at 121 to 135 days of age and 136 to 150 days (p < 0.05). The ADG of blue foxes at 121 to 135 days of age was significantly decreased by VD3 level (p < 0.05). The Ca dosage decreased the nutrient digestibility (p < 0.05). The Ca dosage increased the fecal Ca and P and decreased the P digestibility (p < 0.05). Interactions were found between the Ca and VD3 levels, which affected the digestibility of Ca and P (p < 0.05). In conclusion, this research determined the suitable doses of Ca and VD3 for growing-furring blue foxes.

Vitamin D3 alleviates high-fat induced hepatopancreas lipid accumulation and inflammation by activating AMPKkα/PINK1/Parkin-mediated mitophagy in Litopenaeus vannamei

A high-fat diet (HFD) model was built to elucidate the regulatory mechanisms of vitamin D on lipid metabolism in shrimp. An 8-week feeding trial was aimed to determine whether dietary vitamin D3 would ameliorate the adverse effects of HFD feeding in Litopenaeus vannamei. A total of 360 shrimp (initial weight of 0.50 ± 0.01 g) were randomly divided into three diets with three replicates, and each replication consisted of 40 shrimp. Three experimental diets included the control diet (NFD, 7.36% fat, 45.71% protein), HFD (11.32% fat, 45.89% protein) and the HFD supplemented with 0.57 mg/kg vitamin D3 (HFD+VD). The results revealed that growth performance was not affected (P > 0.05) by different experimental diets in L. vannamei. Compared with the control group, HFD group significantly increased (P < 0.05) serum low-density lipoprotein, cholesterol, triglyceride and hepatopancreas lipid accumulation (confirmed by genes expression, morphology observation and fatty acid composition) in L. vannamei. Hepatopancreas inflammation related gene (tnf-α, rab6a) levels and damaged mitochondria numbers were significantly increased (P < 0.05), while levels of immune related genes (alp, acp, lzm) and mitophagy related genes (ampkα, pink1, parkin, atg13, atg14, atg16, atg101) were decreased (P < 0.05) in L. vannamei. Compared with the HFD group, HFD+VD group significantly decreased (P < 0.05) hepatopancreas lipid deposition in L. vannamei. Hepatopancreas inflammation related genes (tnf-α, aif, rab6a) levels and damaged mitochondria numbers were significantly decreased (P < 0.05), while mitophagy related genes (ampkα, pink1, parkin, becline, atg13, atg14, atg16, atg101, atg9, atg12, lc3) and immune related genes (alp, acp, lzm) were increased (P < 0.05) in L. vannamei. In conclusion, the results of present study showed that: (1) High fat diet could promote hepatopancreas lipid accumulation, increase inflammation and inhibit mitophagy in L.vannamei; (2) Dietary vitamin D3 supplementation could alleviate high-fat induced hepatopancreas lipid accumulation and inflammation by activating AMPKkα/PINK1/Parkin-mediated mitophagy in L.vannamei.

Effects of dietary vitamin D3 supplementation on the growth performance, tissue Ca and P concentrations, antioxidant capacitiy, immune response and lipid metabolism in Litopenaeus vannamei larvae - CORRIGENDUM.

Effects of dietary vitamin D3 supplementation on the growth performance, tissue Ca and P concentrations, antioxidant capacitiy, immune response and lipid metabolism in Litopenaeus vannamei larvae – CORRIGENDUM - Volume 128 Issue 5

Dietary sodium butyrate and/or vitamin D3 supplementation alters growth performance, meat quality, chemical composition, and oxidative stability in broilers

The present study was conducted to elucidate the effects of sodium butyrate (SB) and vitamin D3 (VD3) supplementation on meat quality, oxidative stability, and nutritional value of the broiler chicken. The results indicated that dietary SB decreased lightness (L*), cooking and drip loss, free fatty acids (FFA), C14:0, C16:0, saturated fatty acids (SFA), C20:4n6, and n-6: n3 polyunsaturated fatty acids (PUFA) and increased DPPH and ABTS in chicken meat. The PUFAs content in the chicken meat increased only when SB was added along with higher VD3 levels. However, the amino acid content was reduced with an increase in the VD3 levels. In conclusion, dietary SB supplementation improved chicken meat quality by enhancing the antioxidant capacity and physical properties. Moreover, adding SB or combined with higher VD3 levels optimized the fatty acid composition. However, higher VD3 levels reduced the amino acid content of the chicken meat.

Effects of dietary vitamin D3 supplementation on the growth performance, tissue Ca and P concentrations, antioxidant capacity, immune response and lipid metabolism in Litopenaeus vannamei larvae.

An 8-week feeding trial was conducted to investigate the effects of dietary vitamin D3 supplementation on the growth performance, tissue Ca and P concentrations, antioxidant capacity, immune response and lipid metabolism in Litopenaeus vannamei larvae. A total of 720 shrimp (initial weight 0·50 ± 0·01 g) were randomly distributed into six treatments, each of which had three duplicates of forty shrimp per duplicate. Six isonitrogenous and isolipidic diets were formulated to contain graded vitamin D3 (0·18, 0·23, 0·27, 0·48, 0·57 and 0·98 mg/kg of vitamin D3, measured) supplementation levels. The results revealed that L. vannamei fed diet containing 0·48 mg/kg of vitamin D3 achieved the best growth performance. Compared with the control group, supplementing 0·48 mg/kg of vitamin D3 significantly increased (P < 0·05) the activities of catalase, total antioxidative capacity, alkaline phosphatase and acid phosphatase in serum and hepatopancreas. Expression levels of antioxidant and immune-related genes were synchronously increased (P < 0·05). Carapace P and Ca concentrations were increased (P < 0·05) with the increased vitamin D3 supplementation levels. Further analysis of lipid metabolism-related genes expression showed that shrimp fed 0·48 mg of vitamin D3 per kg diet showed the highest value in the expression of lipid synthesis-related genes, while shrimp fed 0·98 mg of vitamin D3 per kg diet showed the highest value in the expression of lipolysis-related genes. In conclusion, the results of present study indicated that dietary supplementation of 0·48 mg/kg of vitamin D3 could increase Ca and P concentrations, improve antioxidant capacity and immune response, and influence lipid metabolism in L. vannamei.

Vitamin D3 supplementation alleviates chemically-induced cirrhosis-associated hepatocarcinogenesis

Vitamin D3 (VD3) deficiency has been associated with increased risk for cirrhosis and hepatocellular carcinoma, a highly incident malignant neoplasia worldwide. On the other hand, VD3 supplementation has shown some beneficial effects in clinical studies and rodent models of chronic liver disease. However, preventive effects of dietary VD3 supplementation in cirrhosis-associated hepatocarcinogenesis is still unknow. To investigate this purpose, male Wistar rats submitted to a combined diethylnitrosamine- and thioacetamide-induced model were concomitantly supplemented with VD3 (5,000 and 10,000 IU/kg diet) for 25 weeks. Liver samples were collected for histological, biochemical and molecular analysis. Serum samples were used to measure 25-hydroxyvitamin D [25(OH)D] and alanine aminotransferase levels. Both VD3 interventions decreased hepatic collagen deposition and pro-inflammatory p65 protein levels, while increased hepatic antioxidant catalase and glutathione peroxidase activities and serum 25(OH)D, without a clear dose-response effect. Nonetheless, only the highest concentration of VD3 increased hepatic protein levels of VD receptor, while decreased the number of large preneoplastic glutathione-S-transferase- (>0.5 mm²) and keratin 8/18-positive lesions, as well the multiplicity of hepatocellular adenomas. Moreover, this intervention increased hepatic antioxidant Nrf2 protein levels and glutathione-S-transferase activity. In summary, dietary VD3 supplementation - in special the highest intervention - showed antifibrotic and antineoplastic properties in chemically-induced cirrhosis-associated hepatocarcinogenesis. The positive modulation of Nrf2 antioxidant axis may be mechanistically involved with these beneficial effects, and may guide future clinical studies.

Impact of Dietary Vitamin D3 Supplementation on Growth, Molting, Antioxidant Capability, and Immunity of Juvenile Chinese Mitten Crabs (Eriocheir sinensis) by Metabolites and Vitamin D Receptor.

Vitamin D3 (vit-D3), as an indispensable and fat-soluble nutrient, is associated with skeletal mineralization and health in mammals. However, such associations have not been well studied in economically important crustaceans. Six levels of vit-D3 with isonitrogenous and isolipidic diets were used to feed Eriocheir sinensis. The range of optimal vit-D3 requirements is 5685.43-10,000 IU/kg based on growth. The crabs fed 9000 IU/kg vit-D3 showed the best growth performance. This vit-D3 dose significantly increased antioxidant capacity in the hepatopancreas and intestine and was optimal for molting and innate immunity via quantitative polymerase chain reaction analysis. Transcriptomics analyses indicate that vit-D3 could alter protein processing in the endoplasmic reticulum, steroid biosynthesis, and antigen processing and presentation. As shown by the enzyme-linked immunosorbent assay, vit-D3 could improve vitamin D receptor, retinoic acid receptor, and C-type lectins concentrations. The 1α,25-dihydroxy vit-D3 content in serum was significantly higher in 3000-9000 IU/kg vit-D3. The study suggests that dietary vit-D3 and its metabolites can regulate molting and innate immunity in crabs.

Effect of Stocking Density, Dietary Vitamin D3 and Probiotic Supplementation on Carcass Traits and Blood Parameters of Broiler Chickens

The present study was conducted to evaluate the effect of stocking density, dietary supplementation of probiotic and Vitamin D3 on carcass yield and blood biochemistry of broiler chickens. A total number of 360 unsexed broiler chicks (Evian), one-day old, nearly similar in live body weight were used in this study. Chicks were randomly divided into equal 12 treatments in a 2X3X2 factorial arrangement experiment. Birds were allocated in two main experimental groups (each of 180 birds), the first main group kept under normal stocking density (LSD) with 10 birds /m2 and the second main group kept under high stocking density (HSD) with16 birds/m2. Each main group was divided into three groups (each of 60 birds) fed on diets supplemented with probiotic at a levels of 0, 1 and 2 g/kg diet, respectively. Each group divided into two sub-group (each of 30 birds) and supplemented with fed vit.-D3 at a level of 250 and 500 IU/kg diet, respectively. Results obtained showed that raised broiler chickens under LSD had significantly improved absolute and relative carcass, giblets and total edible weight Moreover, it has significantly increased plasma total protein, albumin (A), globulin (G), cholesterol, triglyceride and it has decreased plasma transaminase enzymes of AST and ALT, compared with those rose under HSD. Broiler chicks fed on diet supplemented with probiotic at level of 2 g/ kg diet showed higher plasma total protein, albumin and A/G ratio, cholesterol and triglycerides than those fed on the other levels of probiotic supplementations. While, it has recorded lowest plasma AST and ALT levels, compared with the other experimental groups. Feeding broiler chickens on high level of Vit.-D3 (500 IU/ Kg diet) has significantly increased plasma protein fractions and decreased plasma AST and ALT levels, compared with those fed diet supplemented with low level of Vit.-D3 (250 IU/Kg) that caused significant decreased plasma cholesterol and triglycerides. Finally, it could be recommended to apply LSD (10 birds/ m2), high level of Vit.-D3 (500 IU/ Kg) and probiotic at a level of 2 g/ kg diet to improve carcass yield and blood biochemistry of broiler chickens.

Sexually Dimorphic Effects of Dietary Vitamin D3 Supplementation on Cognition and the Gut Microbiome in Aging Rats (P14-006-19)

ObjectivesIncreasing evidence suggests that vitamin D plays a role in maintaining cognitive function and that vitamin D deficiency may accelerate age-related cognitive decline. Here, we determined if a long-term enhanced vitamin D (VitD3, cholecalciferol) diet, higher than the standard dietary level, maintains or improves cognitive function in aging male and female rats. We also examined if the high VitD3 diet affected the gut microbiome. MethodsBeginning at 12 months of age 20 male and 20 female F344 rats were fed an AIN-93 diet containing either standard (1000 IU/kg diet) or higher (10,000 IU/kg) VitD3 for 6 months. The Morris water maze (MWM) was then used to assess learning and memory. Following the MWM, the gut microbiome from undigested chyme collected from the intestinal cecum was identified and taxonomically classified by Argonne National Laboratory using 16S rRNA sequences. ZRT Laboratory determined 25-(OH)VitD3 levels from cardiac blood. A two-way ANOVA and Tukey post-hoc was used to test for statistical significance. ResultsAfter 3 days of training the probe test on day 4 indicated that the higher VitD3 diet significantly reduced path length and latency (P = 0.01) to the digital platform in females but not males. On day 5 platform location was changed and animals received one day of reversal training. On day 8, three days after reversal training, the reversal probe indicated that higher dietary VitD3 improved performance in males but not females by significantly reducing path length and latency to the digital platform (P < 0.05). Analyses of the cecal microbiome content indicated that for numerous bacteria sex specific differences were present. Further, the Shannon Diversity Index of the gut microbiome indicated a significant treatment effect of higher dietary VitD3 in females (P = 0.01). The higher VitD3 diet significantly elevated 25-(OH)VitD3 blood levels. ConclusionsThese results indicate that a high VitD3 diet may preserve cognitive acuity during aging. Further, VitD3 may have sexually dimorphic effects on memory formation. The present results replicate our previous study that a high VitD3 diet preserves cognition in aging male rats (Latimer et al. 2014). The microbiome showed sexually dimorphic differences and the high VitD3 diet appeared to affect the microbiome in females more than males. The significance of this is not clear. Funding SourcesNIA, NIDDK.

Dietary vitamin D3 supplementation protects laying hens against lipopolysaccharide-induced immunological stress

BackgroundThe effects of vitamin D on the immune function of laying hens are not well understood. This study investigated the effects of vitamin D3 (VD3) on laying performance and immunological functions in laying hens under Escherichia coli lipopolysaccharide (LPS) challenge.MethodsIn experiment one, 360 Jinghong-1 strain layers (32 weeks) were randomly divided into four groups with six replicates per group and 15 hens per replicate. Hens were fed a basal diet supplemented with different levels of VD3 (0; 500; 1500; or 3000 IU VD3/kg of diet) for 10 weeks to determine laying performance, egg quality, and other parameters. In experiment two, 24 Jinghong laying hens (32 weeks) were fed basal diets with either 0 or 3000 IU VD3/kg of diet. After 10 weeks of feeding, six hens from each treatment were injected intravenously with 8 mg/kg of body weight of either LPS or saline. Blood and spleen samples were obtained for immune parameter analysis 4 h after injection.ResultsVD3 deficiency reduced egg production and egg quality; in addition, feed intake and feed-to-egg ratio increased. No significant differences were observed in these parameters except eggshell strength between dietary VD3 supplemental levels at 500; 1500; and 3000 IU VD3/kg of diet. VD3 deficiency increased serum hormone (calcitonin, parathyroid hormone, estradiol, and progesterone) and cytokine (IL-6, IL-10) levels, the ratio of IFN-γ to IL-4, myeloperoxidase activity and total IgG content in the serum, and upregulated the blood CD3+ T cell population. Splenic retinoid X receptor (RXR), nuclear factor-κB (NF-κB), inducible nitric oxide synthase (iNOS), and polymeric immunoglobulin receptor (pIgR) gene mRNA levels were upregulated in VD3-deficienct hens. VD3 deficiency significantly reduced serum Follicle stimulating hormone (FSH) and Luteinizing hormone (LH) concentrations and the number of CD4+CD25+ T cells in the blood. These changes were completely normalized by VD3 sufficiency. LPS reduced serum LH concentration, splenic lysozyme, and pIgR gene mRNA levels. LPS induced an increase in total serum IgM levels and the percentage of CD8+ T cells in the blood. The changes were completely reversed by VD3 addition.ConclusionVD3 supplementation could protect laying hens not only from VD3 deficiency but also from immunological stress.

Effect of dietary vitamin D3 and 25-hydroxyvitamin D3 supplementation on plasma and milk 25-hydroxyvitamin D3 concentration in dairy cows

Milk enriched with vitamin D by supplementing dairy cow diets could provide a valuable dietary source of vitamin D, but information on the feasibility of this approach is limited. In the current study, the effects of supplementing dairy cows with either vitamin D3 or 25(OH)D3 over the transition/early lactation period on plasma and milk vitamin D concentrations were compared. Sixty dairy cows were randomly allocated to 1 of 4 dietary treatments from 14 d precalving to 56 d postcalving. Treatments were a control diet (control) for both precalving and postcalving periods containing 0.625 mg/d of vitamin D3; a precalving diet supplemented with 6 mg of 25(OH)D3/d, but with a postcalving diet matching that of the control diet [25(OH)D3 precalving]; the control diet precalving but with the postcalving diet supplemented with 2 mg of vitamin D3/d (D3max), and the control diet precalving but with the postcalving diet supplemented with 1.5 mg of 25(OH)D3/d [25(OH)D3 postcalving]. No treatment effect on milk yield, composition or 25(OH)D3 concentration was observed. However, an interaction was observed of treatment and time for plasma 25(OH)D3 concentration; this increased within 2 wk of supplementation for the 25(OH)D3 precalving treatment (peaking just after calving, 202 ng/mL), whereas that of the 25(OH)D3 postcalving group had a slower response following supplementation, continuing to increase at 56 d. Correlations were observed between plasma and milk 25(OH)D3 concentrations at d 4 and 14 of lactation, but not at later sampling times. The D3max treatment did not increase 25(OH)D3 concentration in plasma or milk. Overall, results from this study indicate that supplemental 25(OH)D3 is an effective means of enhancing dairy cow plasma 25(OH)D3 concentrations compared with vitamin D3 supplementation, but not necessarily milk concentrations.

Effects of the different levels of dietary vitamin D on boar performance and semen quality

Vitamin D plays a major role primarily in bone mineral homeostasis; however, the action of vitamin D on male reproduction of boars remains unknown. This study was conducted to evaluate the effects of dietary vitamin D3 supplementation on reproductive performance of boars. Twenty-four Yorkshire boars with eighteen months were randomly allocated to one of three vitamin D3 levels diets: 200 IU/kg (C), 2000 IU/kg (T1) and 4000 IU/kg (T2) of vitamin D3 for a 16-week period. Results showed that sperm motility, effective sperm number per ejaculate, acrosome intactness ratio, and membrane intactness ratio in T1 group were significantly higher than those in C group. The sperm membrane intactness ratio was higher in T1 group than in T2 group, whereas the deformity ratio was significantly lower in T1 than in C and T2 groups. Dietary supplementation with vitamin D3 significantly increased 25-OHD3 concentration in the blood and seminal plasma, but there was no significant difference in its concentration in the seminal plasma between T1 and T2 groups. The concentrations of blood testosterone and aromatase activity increased following vitamin D supplementation. Seminal plasma Ca2+, fructose concentration, and acid phosphatase activity were higher in T1 group than in C group, but not significantly different from the corresponding values in T2 group. Furthermore, expression of CYP19, CYP24A1, and VDR mRNAs in sperm was up-regulated in T1 group compared to that in C group. In conclusion, supplementation of boar diets with 2000 IU/kg vitamin D3 increased the sperm motility and effective sperm number, which was in line with the elevated concentrations of vitamin D, hormone secretion and gene expression.

High dose dietary vitamin D3 increases bone mass and strength in mice

Vitamin D plays a critical role in skeletal homeostasis. Vitamin D supplementation is used worldwide to maintain optimal bone health, but the most appropriate level of supplementation remains controversial. This study aimed to determine the effects of varying doses of dietary vitamin D3 on the mechanical properties and morphology of growing bone.Eight-week-old female mice were supplied with one of 3 diets, each containing a different dose of vitamin D3: 1000IU/kg (control), 8000IU/kg or 20,000IU/kg. Mice had ad libitum access to the specialty diet for 4weeks before they were culled and their tibiae collected for further analysis. The collected tibia underwent three-point bending and reference-point indentation from which their mechanical properties were determined, and cortical and trabecular morphology determined by micro computed tomography.Dietary supplementation with 20,000IU/kg vitamin D3 resulted in greater ductility (~200%) and toughness (~150%) compared to the 1000IU/kg control. The 20,000IU/kg diet was also associated with significantly greater trabecular bone volume fraction and trabecular number. The 8000IU/kg diet had no significant effect on trabecular bone mass.We conclude that vitamin D3 supplementation of 20,000IU/kg during early adulthood leads to tougher bone that is more ductile and less brittle than that of mice supplied with standard levels of dietary vitamin D3 (1000IU/kg) or 8000IU/kg. This suggests that dietary vitamin D3 supplementation may increase bone health by improving bone material strength and supports the use of vitamin D3 supplementation, during adolescence, for achieving a higher peak bone mass in adulthood and thereby preventing osteoporosis.

Influence of dietary vitamin D3 supplementation on the color changes in longissimus lumborum, vastus lateralis, semitendinosus, and semimembranosus beef muscles

The aim of this study was to determine the effect of dietary vitamin D3 supplementation on changes in color and heme pigment (myoglobin and metmyoglobin) in 4 beef muscles. The muscles came from 48 crossbred bulls that were subjected to supplementation with vitamin D3 at 4 different doses: 0.0 (control group), 3.5, 7.0, and 10.0 x 106 IU. The 3.5 x 106 IU dose was administered daily for 6 days, before the morning feeding. Four days before slaughter, the supplementation was withdrawn. The dose of 7.0 and 10.0 x 106 IU was administered for 3 days and withdrawn 7 days before slaughter. The data show that supplementation with vitamin D3 had a negative effect on beef meat color (P < 0.05). All analyzed muscles with vitamin D3 had lightness (L*) and yellowness (b*) values higher than those of the control group (P 6lt; 0.05). Furthermore, redness (a*) decreased and metmyoglobin increased as a function of vitamin D3 dose. These negative effects on meat color occurred with 7.0 and 10.0 x 106 IU doses. The muscle microstructure was imaged and it showed the effects of higher Ca2+ concentrations on the deterioration of meat color.