The urgent need to recommend an intake of vitamin D that is effective

Abstract

The report by Hyppönen and Power in this issue of the Journal (1) highlights a frustrating and regrettable situation for nutrition researchers. In the early 1970s, the same serum 25-hydroxyvitamin D [25(OH)D] concentrations reported by Hyppönen and Power were thought to be indicative of "healthy" white adults in the United Kingdom (2). However, during those early years after the discovery of 25(OH)D, the adequacy of its serum concentration was based simply on whether the concentration was enough to prevent osteomalacia or rickets. Three decades later, we know that 25(OH)D concentrations relate to many other aspects of health, including fracture risk, bone density, colon cancer, and even tooth attachment (3); we also know that much higher concentrations of 25(OH)D are needed to prevent adverse outcomes. Indeed, in the 1958 British birth cohort, lower 25(OH)D is associated with a higher percentage of hemoglobin A 1C (a measure of long-term glucose concentration), which further emphasizes the need to maintain optimal 25(OH)D concentrations (4).Randomized trials using the currently recommended intakes of 400 IU vitamin D/d have shown no appreciable reduction in fracture risk (3). In contrast, trials using 700 -800 IU vitamin D/d found less fracture incidence, with and without supplemental calcium (3). The reduction in fracture incidence occurs when mean serum 25(OH)D concentrations exceed 72 nmol/L, and this change may result from both improved bone health and reduction in falls due to greater muscle strength (3). Although it is not yet proven through clinical trials, higher intakes may also reduce the incidence of colon and other cancers, and these relations indicate that the desirable 25(OH)D concentration is ͧ75 nmol/L (3). One recent report associates greater 25(OH)D concentrations with lower risk of nursing home admission; the most desirable category of concentration starts at 75 nmol/L (5).Human diets do not provide sufficient vitamin D; if they did, the abovementioned associations between health and serum 25(OH)D concentrations would not be so routinely observed. The vitamin D provided by foods and supplements is overwhelmed by the effect of skin exposure to ultraviolet B light. Geography, season, skin color, and sun-related behavior are the main predictors of vitamin D nutritional status (6 -10). Correction of low 25(OH)D concentrations can happen only if some or all of the following are implemented: the encouragement of safe, moderate exposure of skin to ultraviolet light; appropriate increases in food fortification with vitamin D; and the provision of higher doses of vitamin D in supplements for adults.Evaluation of most relations of health and disease that involve vitamin D leads to the conclusion that a desirable 25(OH)D concentration is ͧ75 nmol/L (30 ng/mL) (3-5). If a concentration of 75 nmol/L is the goal to be achieved by consumption of vitamin D, then why is it so rare for members of the population to accomplish this? One reason is that almost every time the public media report that vitamin D nutri...

New strategies in sport nutrition to increase exercise performance

“…However, further work is needed to define specific applications including targeted sporting events, benefits to elite vs recreational athletes, and whether other muscle carnosine actions such as Ca handling are also responsible [138]. [143,144]. In our laboratory, we have reported detrimental effects on muscle function when concentrations are below 30nmol/L [140] with no performance enhancing effects of vitamin D supplements if the starting concentration is around 50nmol/L [145].…”

Prevalence and predictors of vitamin D deficiency based on maternal mid-gestation and neonatal cord bloods: The Generation R Study

“…Nearly a quarter (21%) of the mother-infant pairs were exposed to persistent developmental vitamin D deficiency, and this proportion was even higher in families from non-European ancestry (44%). There are safe, cheap and readily-available treatments for vitamin D deficiency (Holick and Chen, 2008, Holick, 2007, Vieth et al, 2007. Our task is to develop public health programs and targeted intervention programs for at-risk groups that address the particular needs of pregnant women and their offspring.…”

Relationship between 25-OH-D serum level and relapse rate in multiple sclerosis patients before and after vitamin D supplementation

“…The spontaneous DSL (before supplementation) was 49 ± 22 nmol/l in our cohort. Therefore, the first aim of our intervention was to bring the DSL of our MS patients to slightly above the 75-100 nmol/l zone, which is often nowadays considered as the critical physiological lower limit for extrabone beneficial effects of vitamin D [Hollis, 2005;Vieth et al 2007;Souberbielle et al 2010], maybe including the prevention of MS [Munger et al 2006]. After adjustments to the vitamin D supplementation dose in some patients, when the DSL either remained below the 75-100 nmol/l zone or transitorily exceeded 200 nmol/l, an averaged serum level of 110 ± 26 nmol/l was reached in this cohort during the follow up (with, therefore, an increase of 60 nmol/l, on average), corresponding to an average daily supplementation of 3010 IU of vitamin D. It should be noted that this supplementation was within the range of 1000-4000 IU/day of vitamin D often nowadays considered as the daily physiological requirement [Heaney et al 2003[Heaney et al , 2009Grant and Holick, 2005;Vieth, 2006;Bischoff-Ferrari et al 2006;Hall et al 2010;Schwalfenberg et al 2010], even if this point is not yet consensual [Ross et al 2011;Heaney and Holick, 2011].…”