OH HO OH Vitamin D in Cattle: Calcium and Beyond Corwin D. Nelson, Ph.D. Assistant Professor of Physiology Department of Animal Sciences
Seminar Outline 1. Basics of vitamin D metabolism and genomic actions 2. Control of calcium and bone classical endocrine role of vitamin D 3. Non-classical functions of vitamin D Immunity 4. Current practices and outcomes of vitamin D nutrition 5. Future perspectives and opportunities
Vitamin D metabolic pathway Skin HO Vitamin D 3 Supplement (40-60 IU/kg BW) 25-Hydroxylase (Liver) (40-80 ng/ml serum) 25-Hydroxyvitamin D 3 25(OH)D 3 24,25 D 3 CYP27B1 = 1 -Hydroxylase 24-Hydroxylase Inactive (Kidneys, Macrophages) (20-100 pg/ml serum) 1,25-Dihydroxyvitamin D 3 1,25(OH) 2 D 3 Active 1,24,25 D 3
Genomic Actions of Vitamin D 1,25-Dihydroxyvitamin D 3 Age and gender Pregnancy and lactation Disease Nutrition and environment HO OH OH VDR Epigenetics Co-stimulation VDR expression D metabolism D binding proteins RXR Mineral related Kidneys/intes nes TRPV6 Calbindins 9k, 28k CYP24A1 Bones RANKL FGF23 Osteopon n Osteocalcin Vitamin D Receptor 1, VDR Re noid X Receptor RXR Vitamin D Response Element Nucleus Immune related Macrophage inos RANTES DEFB3,4,6,7,10 Mammary CYP24A1 inos DEFB4 p21
Regulation of Renal Vitamin D Metabolism Normal Conditions Urine Ca P i Ca Ca Ca P P i i P i PTH Intestine Ca 1 -OHase 1, 1, P i FGF-23 24-OHase 1,24,
Regulation of Renal Vitamin D Metabolism Low Ca & P i Urine Ca P i Ca Ca Ca P P i i P i (-) Ca PTH 1 -OHase 1, 1,25D 1, 3 Intestine Ca P i FGF-23 24-OHase 1,24,
Regulation of Renal Vitamin D Metabolism Vitamin D Deficient (<10 ng /ml serum) Deficient (Rickets) Insufficient Sufficient (Normal) Above Normal 0 10 30 80 100 Serum [25(OH)D 3 ] (ng/ml) Urine Ca P i Ca Ca Ca P P i i P i Excess? (-) Ca PTH Intestine Ca 1, 1 -OHase 1, P i FGF-23 24-OHase 1,24,
Regulation of Renal Vitamin D Metabolism High Vitamin D (>100 ng /ml serum) Urine Deficient (Rickets) Insufficient Ca P i Ca Ca Ca Sufficient (Normal) P P i i P i Above Normal 0 10 30 80 100 Serum [25(OH)D 3 ] (ng/ml) Excess? PTH 25D 1 -OHase 1, 3 FGF-23 24-OHase Intestine Ca P i 1,24,
Non-Classical Actions of Vitamin D: Immunity Vit D 3 Liver Blood 1, Toll-like receptor CYP27B1 Vitamin D receptor 1, Vitamin D receptor Nitric Oxide β-defensins Macrophage RANTES
Activation of the vitamin D pathway in bovine immunity LPS Milk #transcripts/10 3 RPS9 10 3 10 2 10 1 10 0 Blood Cntrl LPS CYP27B1 * * 10-1 Neutrophils Macrophages Cell Sorter Neutrophils Macrophages #transcripts/10 3 RPS9 10 3 10 2 10 1 Blood Cntrl LPS VDR * * 10 0 Neutrophils Macrophages
Vitamin D helps activate antimicrobial defenses Vit D 3 Liver Blood Toll-like receptor 1, 1, CYP27B1 Vitamin D receptor Inducible Nitric Oxide Synthase Vitamin D (inos) receptor Nelson, 2010 J. Dairy Sci. Macrophage RANTES Relative fold increase [NO 2 - ], mm Nitric Oxide β-defensins 20 15 10 5 0 30 25 20 15 10 5 0 inos mrna P < 0.001, n = 6 Nitric oxide production P < 0.001, n = 6 0 25 50 75 100 25(OH)D 3 dose (ng/ml)
Vitamin D helps activate antimicrobial defenses Vit D 3 Liver Blood Toll-like receptor Bovine β-defensins 1, 1, CYP27B1 Vitamin D receptor Vitamin D receptor Macrophage Nature Reviews Immunology 3, 710-720 (September 2003) RANTES Nitric Oxide β-defensins Merriman, 2015. J. Steroid Biochem. Mol. Biol. #transcripts/10 3 RPS9 #transcripts/10 3 RPS9 300 200 100 1000 800 600 400 200 BNBD3 *** *** *** 0 0 25 50 75 100 25D concentration ng/ml BNBD7 ** ** *** 0 0 25 50 75 100 25D concentration ng/ml
Vitamin D helps activate antimicrobial defenses (Effects of intramammary 1,25D during mastitis) Placebo 10 ug 1,25D inos/10 3 RPS9 600 400 200 * ** inos P = 0.008 * bbd4/10 3 RPS9 300 200 100 DEFB4 * P = 0.02 bbd7/10 3 RPS9 150 100 50 bbd7 * * ** P = 0.009 0 0 12 24 36 48 60 72 0 0 12 24 36 48 60 72 0 0 12 24 36 48 60 72 Time relative to treatment, hours
Somatic Cell Count (X10-5 /ml) Bacterial Count (Log cfu/ml) Vitamin D helps activate antimicrobial defenses 10 Cows infected (Strep. uberis) 8 6 Placebo 4 P < 0.05 Placebo 25(OH)D 3 2 25(OH)D 3 Milk samples (2X per day) 0 Placebo 16 100 μg 25(OH)D 3 12 8 Placebo 4 Bacterial counts Somatic cell counts 0 0 1 2 3 4 5 6 7 8 9 10 Milkings after infection 25(OH)D 3 Lippolis, 2011 Lippolis et al. 2011, PLoS ONE
Ongoing Investigations Vit D 3 Liver Blood Toll-like receptor 1, CYP27B1 Co-stimulatory signals? Vitamin D receptor? 1, Mechanism of action: VDR binding sites and direct targets Vitamin D receptor Macrophage RANTES Nitric Oxide β-defensins? Antimicrobial activity
Implications of Vitamin D in Bovine Immunity Vit D 3 Liver Blood 1, Mastitis Toll-like receptor 1, CYP27B1 Vitamin D receptor Vitamin D receptor Macrophage RANTES Nitric Oxide β-defensins Metritis Respiratory Diseases Gut Health
Non-calcemic Actions of Vitamin D (Where is the receptor?) Brain Liver Adipose Calcemic actions: Bone Kidney Intestines Immune Cells Reproductive organs Muscle Mammary gland
Current Practices and Outcomes of Vitamin D Nutrition Serum or plasma 25(OH)D concentrations is the best marker of vitamin D status Deficient (Rickets) Insufficient??? Sufficient (Normal) Above Normal 0 10 30 80 100 Serum [25(OH)D 3 ] (ng/ml) Excess???? Optimal 25(OH)D concentrations for health and performance are still unknown
Vitamin D requirements of Cattle
Number of Cows 150 100 50 Vitamin D Status of Dairy Cows Distrubution of Serum 25(OH)D: Dairy Cattle Serum 25(OH)D concentrations of 642 samples collected from 10 different dairy herds. Cows received 30K-50K IU vitamin D3 daily 0 20 40 60 80 100 120 140 Serum 25(OH)D (ng/ml) Nelson 2016, J. Dairy Science, 99:10150-10160
Vitamin D Status of Dairy Calves Serum 25(OH)D (ng/ml) 120 100 80 60 40 20 0 0 7 14 21 28 35 42 Age (weeks) Milk replacer with 11,000 IU vitamin D/kg DM Milk replacer with 6,600 IU vitamin D/kg DM Calves fed whole milk Nelson 2016, J. Dairy Science, 99:10150-10160
Serum 25(OH)D (ng/ml) 200 175 150 125 100 Recommendations for Dairy Calves 75 50 25 0 0 7 14 21 28 35 42 49 56 Age (days) Nelson 2016, J. Dairy Science, 99:10150-10160 IU/kg DM 17900 11000 1700 400
Recommendations for Dairy Calves Serum 25(OH)D (ng/ml) 200 175 150 125 100 75 50 25 Y = 6.6*X + 16 Risks and benefits of excess vitamin D still unknown Dose-response relationship is not maintained in cows 6,000 10,000 IU vitamin D 3 /kg DM (~60-100 IU/kg BW) 0 0 5 10 15 20 Supplemental Vitamin D 3 (KIU/kg DM) Nelson 2016, J. Dairy Science, 99:10150-10160
Future Perspectives: Effects of dietary 25-hydroxyvitamin D (HyD ) 25-Hydroxylase (Liver) HO Vitamin D 3 Unlimited Activity? 25-Hydroxyvitamin D 3 25(OH)D 3 1 -Hydroxylase (Kidneys, Macrophages) Rate Limiting Step 1,25-Dihydroxyvitamin D 3 1,25(OH) 2 D 3 Active
Effects of dietary 25-hydroxyvitamin D (HyD ) on vitamin D metabolism and immunity of dairy cows Hypothesis: Increased serum concentrations of 25D that result from feeding 25D will improve innate immunity of dairy cattle. Cows and treatments: Sixty Holstein cows (120-250 DIM, pregnant) randomly assigned to four treatment groups based on parity and milk yield. -1mgD: supplement containing 1 mg (40,000 IU) vitamin D 3-1mgHyD: supplement containing 1 mg 25-hydroxyvitamin D 3-3mgD: supplement containing 3 mg (120,000 IU) vitamin D 3-3mgHyD: supplement containing 3 mg 25-hydroxyvitamin D 3 Treatments fed individually for 28 days. Experimental mastitis induced at day 21 of the trial.
Effects of dietary 25-hydroxyvitamin D (HyD ) on vitamin D metabolism and immunity of dairy cows Serum 25(OH)D (ng/ml) 300 250 200 150 100 50 0 0 7 14 21 28 Day of Feeding 3mg HyD 1mg HyD 3mg VitD 1mg VitD Poindexter and Nelson, unpublished data
20 Effects of dietary 25-hydroxyvitamin D (HyD ) on vitamin D metabolism and immunity of dairy cows Effect of Feeding HyD on Serum Vitamin D P < 0.001 Serum vitamin D (ng/ml) 15 10 5 25-Hydroxylase (Liver) HO Vitamin D 3 25-Hydroxyvitamin D 3 25(OH)D 3 Limited Activity 0 1mgD 1mgHyD 3mgD 3mgHyD Poindexter and Nelson, unpublished data
Conclusion: Known and unknown of vitamin D physiology Vitamin D receptor and enzyme activity extend beyond calcium homeostasis < 6 IU/kg BW Achieved with ~60 IU/kg BW Requires dietary HyD Deficient (Rickets) Insufficient Sufficient (Normal) Above Normal Excess? 0 10 30 80 100 Serum [25(OH)D 3 ] (ng/ml) Impaired immunity? Impaired reproductive function? Risk: Hypercalcemia? Benefits: Growth, lactation, immunity?
Thank you! /Obrigado! Corwin Nelson, Ph.D. Contributors University of Florida: Kathryn Merriman Michael Poindexter Mercedes Kweh Jose Santos, Ph.D. DSM: Mark Engstrom, Ph.D. Pietro Celi, Ph.D. Scot Williams, Ph.D.