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

Department of Food and Nutritional Sciences, University College, Cork, Ireland.
American Journal of Clinical Nutrition (Impact Factor: 6.77). 03/2009; 89(5):1366-74. DOI: 10.3945/ajcn.2008.27334
Source: PubMed


Older 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.
The 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.
A 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.
Clear 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.
To 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 as ISRCTN registration no. ISRCTN20236112.

Download full-text


Available from: Alice Lucey, Jan 07, 2015
  • Source
    • "Accordingly, the relation between increase of plasma 25(OH)D (131 nmol/L) and vitamin D intake or supplement (31 μg/d), also calculated as the efficacy or efficiency of dietary vitamin D on vitamin D status, was approximately 4.2 nmol/L per μg/d. In human studies, these values ranging between 0.6 and 2.9 nmol/L per μg/d were reported [34–38]. For example, when food was fortified over a range of 3–25 μg/d vitamin D, the plasma 25(OH)D concentration rose over a range of 14 and 35 nmol/L [37]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Calcium and vitamin D deficiency impairs bone health and may cause rickets in children and osteomalacia in adults. Large animal models are useful to study experimental osteopathies and associated metabolic changes. We intended to modulate vitamin D status and induce nutritional osteomalacia in minipigs. The control group (n = 9) was fed a semisynthetic reference diet with 6 g calcium and 6,500 IU vitamin D3/kg and the experimental group (n = 10) the same diet but with only 2 g calcium/kg and without vitamin D. After 15 months, the deficient animals were in negative calcium balance, having lost bone mineral density significantly (means ± SEM) with -51.2 ± 14.7 mg/cm(3) in contrast to controls (-2.3 ± 11.8 mg/cm(3)), whose calcium balance remained positive. Their osteoid surface was significantly higher, typical of osteomalacia. Their plasma 25(OH)D dropped significantly from 60.1 ± 11.4 nmol/L to 15.3 ± 3.4 nmol/L within 10 months, whereas that of the control group on the reference diet rose. Urinary phosphorus excretion and plasma 1,25-dihydroxyvitamin D concentrations were significantly higher and final plasma calcium significantly lower than in controls. We conclude that the minipig is a promising large animal model to induce nutritional osteomalacia and to study the time course of hypovitaminosis D and associated functional effects.
    Full-text · Article · Aug 2013
  • Source
    • "In any case, for both nutrients, epidemiologic dietary surveys indicate that calcium intake remains inadequate in several life stages [6] [8] [10] and a worse picture has been observed for vitamin D, where average intake is under recommended levels for almost everyone. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Objective: In addition to the importance of adequate calcium and vitamin D status for health and prevention of several chronic diseases, a high prevalence of both nutrient inadequacy and 25-hydroxyvitamin D (25[OH]D) insufficiency has been observed. The aim of this study was to estimate calcium and vitamin D status correlates and adequacy from a population-based epidemiologic study. Methods: This is a subsample of a cross-sectional study of a representative sample of individuals living in São Paulo that includes 636 participants. A 24-h dietary record and a blood sample were collected. Nutrient adequacy was estimated by adjusting for the within-person variance of the nutrient intake. Serum concentration of 25(OH)D was measured by high-performance liquid chromatography and considered adequate when ≥ 50 nmol/L. Results: Calcium and vitamin D intake decrease according to life stages in both men and women, and increases with family income and educational level. The prevalence of calcium intake inadequacy is higher than 70% and almost 100% for vitamin D. The highest 25(OH)D concentration was observed in the fall-51.7 (20.4) nmol/L-and lowest in the summer-30.1 (8.8) nmol/L. Sex, body mass index, physical activity, alcohol and smoking habits, life stage, family income, skin color, waist circumference, and season of the year could explain 22% of the variability of 25(OH)D. Conclusions: The present study demonstrates important inadequacies regarding the nutritional status of calcium and vitamin D and indicates an urgent need not only for health professionals, but also for government and food industries to undertake new initiatives that could result in a real improvement in terms of calcium and vitamin D nutrition.
    Full-text · Article · Feb 2013 · Nutrition
  • Source
    • "The European dietary recommendation (PRI) for vitamin D for adults also reveals considerable uncertainty about the available evidence on which to base a recommended intake, as it ranges from 0 to 10 µg/d to account not only for the knowledge gaps but also for the widely varying latitudes that EU citizens live in (35–70°N), assuming a higher dietary requirement in more northerly latitudes but not having data to base a requirement on (23). Two recent controlled, randomized, double-blind vitamin D3 intervention trials, the first in 245 adults aged 20–40 years (24) and the second in 225 community-dwelling adults over 64 years (25), showed that the estimated dietary requirements (covering needs of 97.5% of population) for vitamin D in men and women (aged 20–40 years and 64+ years) to maintain serum 25(OH)D above 25 nmol/L during winter were 8.6 and 8.7 µg/d, respectively. Using the 50 nmol/L cutoff, the requirements raised to 24.7 and 28.0 µg/d for 20–40 and 64-year-olds, respectively. "
    [Show abstract] [Hide abstract]
    ABSTRACT: There is little doubt that vitamin D deficiency across all age groups in Europe is a problem. Low vitamin D status arises due to limited, if any, dermal synthesis during the winter months at latitudes above 40°N, putting increased importance on dietary supply of the vitamin. However, dietary intakes by most populations are low due to the limited supply of vitamin D-rich foods in the food chain. Thus strategies that effectively address this public health issue are urgently required. It has been emphasized and re-emphasized that there are only a limited number of public health strategies available to correct low dietary vitamin D intake: (1) improving intake of naturally occurring vitamin D-rich foods, (2) vitamin D fortification (mandatory or voluntarily) of food, and (3) vitamin D supplementation. Recent evidence suggests that the levels of vitamin D added to food would need to be high so as to ensure dietary requirements are met and health outcomes optimized. In addition, knowledge of the most effective forms of vitamin D to use in some of these preventative approaches is important. There is still uncertainty in relation to the relative efficacy of vitamin D(2) versus D(3), the two main food derived forms and those used in vitamin D supplements. The major metabolite of vitamin D with biological activity is 1,25(OH)(2)D; however, this is usually used for pharmacological purposes and is not typically used in normal, healthy people. The other major metabolite, 25(OH)D, which has also been used for pharmacological purposes is present in certain foods such as meat and meat products (particularly offal) as well as eggs. This metabolite may have the potential to boost vitamin D status up to five times more effectively that native vitamin D(3) in foods. However, the exact bioactivity of this compound needs to be established.
    Full-text · Article · Apr 2012 · Food & Nutrition Research
Show more