Alterations of vitamin D metabolism and requirements in clinical conditions with impaired gastro-intestinal and renal function and in critical illness

Schoenmakers, Inez, Forbes, Alastair and Jones, Kerry S. (2026) Alterations of vitamin D metabolism and requirements in clinical conditions with impaired gastro-intestinal and renal function and in critical illness. The Journal of Steroid Biochemistry and Molecular Biology, 257.

Full text not available from this repository. (Request a copy)

Abstract

Many studies show inverse relationships between the prevalence and severity of clinical conditions and vitamin D status. This may be partly due to reverse causality because of altered organ function, influencing vitamin D metabolism and bioavailability. Here we provide a narrative review of the impact of clinical conditions on vitamin D metabolism reviewing intestinal absorption, vitamin D binding protein (DBP) function and renal metabolism. Dietary vitamin D absorption is dependent on its incorporation in fat droplets in chylomicrons. Gastrointestinal inflammation and impaired fat digestion and absorption lead to decreased vitamin D bioavailability, whereas the hydroxylated form, 25-hydroxyvitamin D (25(OH)D), is less dependent on these factors. Vitamin D metabolites circulate predominantly bound to DBP which facilitates transportation, cellular uptake and regulates hydroxylation into 1,25-dihydroxy vitamin D (1,25(OH)2D) and catabolic products. DBP also plays a key role in scavenging of actin upon cellular damage and inflammation and activation of the innate immune response. A decline in DBP due to actin-scavenging leads to alterations in vitamin D binding, bioavailability and metabolism. The kidney has several roles in vitamin D metabolism: internalisation and hydroxylation of 25(OH)D into 1,25(OH)2D and catabolites and reabsorption of DBP-vitamin D metabolite complex from the glomerular filtrate. Renal damage leads to impairment of these functions. Specific guidance on vitamin D requirements accounting for alterations in vitamin D physiology with many clinical conditions is lacking, except for chronic kidney disease. Understanding how clinical conditions alter organ function and vitamin D metabolism is essential for management of vitamin D status and function.

Item Type:	Article
Additional Information:	Publisher Copyright: © 2025 The Authors
Uncontrolled Keywords:	chronic kidney disease,intestinal absorption,vitamin d,vitamin d binding protein,vitamin d requirements,endocrinology,molecular medicine,molecular biology,biochemistry,clinical biochemistry,endocrinology, diabetes and metabolism,cell biology ,/dk/atira/pure/subjectarea/asjc/1300/1310
Faculty \ School:	Faculty of Medicine and Health Sciences > Norwich Medical School
UEA Research Groups:	Faculty of Medicine and Health Sciences > Research Groups > Nutrition and Preventive Medicine Faculty of Medicine and Health Sciences > Research Groups > Musculoskeletal Medicine Faculty of Medicine and Health Sciences > Research Centres > Metabolic Health Faculty of Medicine and Health Sciences > Research Centres > Norwich Institute for Healthy Aging Faculty of Medicine and Health Sciences > Research Groups > Gastroenterology and Gut Biology
Related URLs:	https://www.scopus.com/pages/publication...
Depositing User:	LivePure Connector
Date Deposited:	30 Apr 2026 07:50
Last Modified:	30 Apr 2026 23:33
URI:	https://ueaeprints.uea.ac.uk/id/eprint/102841
DOI:	10.1016/j.jsbmb.2025.106909

Actions (login required)

View Item