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Title: B-vitamins and healthy ageing
Author: Hughes, Catherine Frances
ISNI:       0000 0004 2720 1953
Awarding Body: University of Ulster
Current Institution: Ulster University
Date of Award: 2010
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B-vitamin deficiency may contribute to age-related diseases. Low/deficient vitamin B 12 status is of particular concern in older people despite the fact that intakes of B 12 typically far exceed current recommendations. Pernicious anaemia accounts for a very small proportion of low/deficient status, however, a much more prevalent problem is food-bound vitamin B 12 malabsorption. Proton pump inhibitor [PPI] drugs are acid suppressant drugs which reduce gastric acid secretion [hypochlorhydria] and could thus potentially reduce the absorption of food-bound vitamin B 12. Using an experimental model of hypochlorhydria, the current results showed no evidence of vitamin B 12 depletion as a result of short-term PPI administration. Long-term PPI usage was however shown to be associated with an increased risk of vitamin B 12 deficiency but this appeared to be alleviated by the regular consumption of foods fortified with the vitamin, with a 19% prevalence of vitamin B 12 deficiency found in long-term PPI users who were non-consumers compared to a 2% prevalence in consumers. Overall the results highlight the importance of fortified food consumption in maintaining vitamin B 12 status, particularly in those at risk of food bound malabsorption owing to PPI usage. This thesis also demonstrated that low dose vitamin B 12 (1μg/d) supplementation can significantly increase vitamin B 12 status both in healthy people and in long-term PPl users. Of note, the investigation of vitamin B 12 biomarker responses to vitamin B 12 depletion and repletion study presented in this thesis indicated that holotranscobalamin (holoTC) was a more sensitive biomarker of vitamin B 12 status and responded quicker to changes in vitamin B 12 status than the more conventional biomarker, serum total B 12. One of the most important findings of this thesis was that low vitamin B6 status was associated with a 6-fold increased risk of cognitive decline in a cohort of healthy older adults investigated over a 4 year period. This largely overlooked B- vitamin may have an important role to play in maintenance of cognitive function in healthy ageing.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available