Vitamin D and healthrelated quality of life in a

Authors: Y S Chao J P Ekwaru A Ohinmaa G Griener P J Veugelers

Publish Date: 2014/04/24

Volume: 23, Issue: 9, Pages: 2569-2575

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Abstract

We analysed baseline data of 1493 Canadians aged 50 years and over in Alberta on HRQOL EQ5D5L and serum 25hydroxyvitamin D 25OHD as a measure of vitamin D status We applied multivariable regression methods to examine the association between vitamin D status and each of the five dimensions and the summary index of the EQ5D5LParticipants with higher serum 25OHD levels were significantly less likely to report problems with mobility usual activities and depression and anxiety Specifically age and genderadjusted odds ratios for reporting problems with mobility usual activities and depression and anxiety were 058 95  confidence interval 044–078 067 050–089 and 067 051–088 per 100 nmol/L increase in 25OHD respectively No significant associations were observed for problems with selfcare and with pain and discomfort HRQOL scores combining the responses of each of the five dimensions increased significantly with increasing serum 25OHD levelsThis is the first study to reveal the importance of vitamin D for the five dimensions of HRQOL in a communitybased sample The observed associations of vitamin D and HRQOL call for intervention studies to strengthen the evidence of the potential benefits of vitamin D supplementation for HRQOL among older adultsVitamin D has been shown to affect bone health and various chronic diseases 1 To mediate on the burden of some of these conditions the Institute of Medicine and Health Canada recommend vitamin D supplementation of 600 IU per day for adults and 800 IU per day for those above the age of 70 years 2 3 Supplementation may be particularly important to residents of northern geographies such as Canada as subcutaneous creation of vitamin D by sun exposure is limited 4 In Canada vitamin D deficiency and insufficiency continue to be prevalent despite the recommendations for Vitamin D supplementation 5 Specifically the Canadian Health Measures Survey had shown that 41 and 106  95  confidence interval 29–58 and 82–136  respectively of Canadians aged 6–79 years had serum 25hydroxyvitamin D 275 and 375 nmol/L respectively 5 We recently showed that the rates of deficiency and insufficiency were 3 and 8  respectively in a sample of working age Canadians 6For older populations several vitamin D supplementation studies have suggested though not consistently less functional limitation 7 prevention of falls 8 9 10 reductions in fractures 11 12 13 and mental health benefits 14 15 A metaanalysis by BischoffFerrari et al 9 concluded that in order to achieve a reduction in falls a supplementation dose of 700–1000 IU per day is needed which is close to what is currently recommended by the Institute of Medicine The above studies suggest a relationship of vitamin D and objectively measured health conditions Healthrelated quality of life HRQOL aims to quantify the subjective experiences of the consequences of these health conditions The importance of vitamin D for HRQOL has been less studied Huang et al 16 attributed improvements in quality of life along with improvements in pain and sleep to vitamin D supplementation in a case series of individuals with chronic pain However to the best of our knowledge no earlier studies have examined the association of vitamin D with the full spectrum of HRQOL in healthy populations We believe that this is particularly important as the Institute of Medicine recommendations are issued to the general public We also believe these are particular important to Canadians given the relatively high latitude and consequent reliance on vitamin D from diet and supplements In the present study we assess the association of vitamin D status and HRQOL among older residents of CanadaThis is a crosssectional study based on information gathered at baseline visits from volunteer participants before starting a wellness programme by the Pure North S’Energy Foundation PN PN a charitable notforprofit organization provides a lifestyle counselling programme as described in more detail elsewhere 6 17 18 As of August of 2012 PN started the recruitment of older residents of the city of Calgary Alberta Canada PN advertised their programme for seniors through local newsletters and through the distribution of flyers in senior homes and community centres PN would organize weekly information meetings after which attendees could elect to sign up to enrol the programme The present study pertains to baseline observations of older residents recruited between August 2012 and April 2013At their baseline visit participants completed a survey had their body height and weight measured and their blood drawn for the assessment of serum 25hydroxyvitamin D 25OHD The survey included the fivelevel EQ5D EQ5D5L to measure healthrelated quality of life HRQOL 19 The EQ5D consists of a fivedimensional descriptive system asking whether participants have 1 no problems 2 slight problems 3 moderate problems 4 severe problems or 5 extreme conditions or are unable to perform or extreme conditions are fully constrained or restricted with each of the following 1 mobility 2 selfcare 3 usual activities 4 pain or discomfort and 5 anxiety or depression 19 HRQOL scores are based on responses to each of the five dimensions and were derived from the USA value sets 20 The EQ5D is an established and validated instrument 19 with the major advantages of being short and easy to complete 21

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