Related Experiment Video
Updated: Aug 23, 2026

Equine Enteric Glial Culture and Application to the Study of a Neural Inflammatory Mechanism in Equine Colic
Published on: October 4, 2024
Daily rhythm of circulating fat soluble vitamin concentration (A, D, E and K) in the horse
Giuseppe Piccione1, Anna Assenza, Fortunata Grasso
1Dipartimento di Morfologia, Biochimica, Fisiologia e Produzioni Animali - Facoltà di Medicina Veterinaria - Sezione di Fisiologia Veterinaria - Università degli Studi di Messina - Polo Universitario dell'Annunziata - 98168 Messina - Italy. giuseppe.piccione@unime.it
Abstract:
BACKGROUND: Many physiological processes of mammalian species exhibit daily rhythmicity. An intrinsic relationship exists between fat soluble vitamins (A, D, E and K) and several body functions. Few investigations on the rhythmic pattern of vitamins in domestic animals have been carried out. The present study evaluated the circadian rhythmicity of fat soluble vitamins in the horse. METHODS: Blood samples from 5 Thoroughbred mares were collected at four-hour intervals over a 48-hour period (starting at 8:00 hours on day 1 and finishing at 4:00 on day 2) via an intravenous cannula inserted into the jugular vein. Fat soluble vitamin concentration in the serum (A, D, E and K) was measured by HPLC. One-way repeated measures analysis of variance (ANOVA) was used to determine significant differences. p values < 0.05 were considered statistically significant. RESULTS: ANOVA showed a highly significant effect of time in all the horses for the vitamins studied (p < 0.0001). The application of the periodic model and the statistical analysis of the "Cosinor" enabled us to define the periodic parameters and their acrophases (expressed in hours) during the 2 days of monitoring: all the studied vitamins showed diurnal acrophases with values between 15:16 and 18:08 hours. CONCLUSION: Fat soluble vitamins exhibit daily rhythmicity with diurnal peak. Further investigations could help optimize the use of these substances according to their circadian (or other) rhythms.
Related Concept Videos
Effect of Hepatic Disease on Pharmacokinetics: Pathophysiologic Assessment and Liver Function Test
Estimation of k and VD of Aminoglycosides
Effect of Hepatic Disease on Pharmacokinetics: Active Drug, Metabolite and Fraction of Metabolized Drug
Effect of Hepatic Disease on Pharmacokinetics: Drug Dosing and Hepatic Blood Flow
EDTA: Conditional Formation Constant
For the equilibrium reaction of the metal with the Y4− form of EDTA, the formation...
Role of Skin in Vitamin D Synthesis
The solar UV B rays (290-315 nm) are absorbed by the skin, and 7-dehydrocholesterol (provitamin D3) photolyzes it to previtamin D3, which undergoes a rapid transformation to vitamin D3(cholecalciferol).
