• Am. J. Clin. Nutr. · May 2009

    Randomized Controlled Trial

    Estimation of the dietary requirement for vitamin D in free-living adults >=64 y of age.

    • Kevin D Cashman, Julie Mw Wallace, Geraldine Horigan, Tom R Hill, Maria S Barnes, Alice J Lucey, Maxine P Bonham, Nicola Taylor, Emeir M Duffy, Kelly Seamans, Siobhan Muldowney, Anthony P Fitzgerald, Albert Flynn, J J Strain, and Mairead Kiely.
    • Department of Food and Nutritional Sciences, University College, Cork, Ireland.
    • Am. J. Clin. Nutr. 2009 May 1; 89 (5): 1366-74.

    BackgroundOlder adults may be more prone to developing vitamin D deficiency than younger adults. Dietary requirements for vitamin D in older adults are based on limited evidence.ObjectiveThe objective was to establish the dietary intake of vitamin D required to maintain serum 25-hydroxyvitamin D [25(OH)D] concentrations above various cutoffs between 25 and 80 nmol/L during wintertime, which accounted for the effect of summer sunshine exposure and diet.DesignA randomized, placebo-controlled, double-blind, 22-wk intervention was conducted in men and women aged >/=64 y (n = 225) at supplemental levels of 0, 5, 10, and 15 microg vitamin D(3)/d from October 2007 to March 2008.ResultsClear dose-related increments (P < 0.0001) in serum 25(OH)D were observed with increasing supplemental vitamin D(3) intakes. The slope of the relation between total vitamin D intake and serum 25(OH)D was 1.97 nmol . L(-1) . microg intake(-1). The vitamin D intake that maintained serum 25(OH)D concentrations >25 nmol/L in 97.5% of the sample was 8.6 microg/d. Intakes were 7.9 and 11.4 microg/d in those who reported a minimum of 15 min daily summer sunshine exposure or less, respectively. The intakes required to maintain serum 25(OH)D concentrations of >37.5, >50, and >80 nmol/L in 97.5% of the sample were 17.2, 24.7, and 38.7 microg/d, respectively.ConclusionTo ensure that the vitamin D requirement is met by the vast majority (>97.5%) of adults aged >/=64 y during winter, between 7.9 and 42.8 microg vitamin D/d is required, depending on summer sun exposure and the threshold of adequacy of 25(OH)D. This trial was registered at http://www.controlled-trials.com/ISRCTN20236112 as ISRCTN registration no. ISRCTN20236112.

      Pubmed     Full text   Copy Citation     Plaintext  

      Add institutional full text...

    Notes

     
    Knowledge, pearl, summary or comment to share?
    300 characters remaining
    help        
    You can also include formatting, links, images and footnotes in your notes
    • Simple formatting can be added to notes, such as *italics*, _underline_ or **bold**.
    • Superscript can be denoted by <sup>text</sup> and subscript <sub>text</sub>.
    • Numbered or bulleted lists can be created using either numbered lines 1. 2. 3., hyphens - or asterisks *.
    • Links can be included with: [my link to pubmed](http://pubmed.com)
    • Images can be included with: ![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
    • For footnotes use [^1](This is a footnote.) inline.
    • Or use an inline reference [^1] to refer to a longer footnote elseweher in the document [^1]: This is a long footnote..

    hide…