Including Food 25-Hydroxyvitamin D in Intake Estimates May Reduce the Discrepancy between Dietary and Serum Measures of Vitamin D Status

Abstract

The discrepancy between the commonly used vitamin D status measures-intake and serum 25-hydroxyvitamin D [25(OH)D] concentrations--has been perplexing. Sun exposure increases serum 25(OH)D concentrations and is often used as an explanation for the higher population-based serum concentrations in the face of apparently low vitamin D intake. However, sun exposure may not be the total explanation. 25(OH)D, a metabolite of vitamin D, is known to be present in animal-based foods. It has been measured and reported only sporadically and is not currently factored into U.S. estimates of vitamin D intake. Previously unavailable preliminary USDA data specifying the 25(OH)D content of a subset of foods allowed exploration of the potential change in the reported overall vitamin D content of foods when the presence of 25(OH)D was included. The issue of 25(OH)D potency was addressed, and available commodity intake estimates were used to outline trends in projected vitamin D intake when 25(OH)D in foods was taken into account. Given the data available, there were notable increases in the total vitamin D content of a number of animal-based foods when potency-adjusted 25(OH)D was included, and in turn there was a potentially meaningful increase (1.7-2.9 μg or 15-30% of average requirement) in vitamin D intake estimates. The apparent increase could reduce discrepancies between intake estimates and serum 25(OH)D concentrations. The relevance to dietary interventions is discussed, and the need for continued exploration regarding 25(OH)D measurement is highlighted.

Relative importance of summer sun exposure, vitamin D intake, and genes to vitamin D status in Dutch older adults: The B-PROOF study

“…This suggests that the reported vitamin D intake estimates were reasonably accurate. In both studies, however, vitamin D intake may be underestimated as evidence indicates that certain foods may contain 25(OH)D, while food consumption tables do not yet account for this [24]. Taking into account 25(OH)D in animal-based foods may result in vitamin D intake estimates that are about 1.7-2.9 mg/day higher than current estimates [24].…”

“…In both studies, however, vitamin D intake may be underestimated as evidence indicates that certain foods may contain 25(OH)D, while food consumption tables do not yet account for this [24]. Taking into account 25(OH)D in animal-based foods may result in vitamin D intake estimates that are about 1.7-2.9 mg/day higher than current estimates [24]. Finally, assessment of habitual sun exposure can be considered suboptimal, which probably resulted in an underestimation of the explained variation in 25(OH)D concentrations resulting from UV-B exposure.…”

Vitamin D deficiency is common among adults in Wallonia (Belgium, 51°30′ North): findings from the Nutrition, Environment and Cardio-Vascular Health study

“…Otherwise, it would be interesting to take into account the 25(OH)D contained in animal-based foods. Studies suggest that true vitamin D intakes will be higher when nutrient database will include potencyadjusted 25(OH)D amounts [32]. Unfortunately, it is not currently possible because studies that have examined his food contents are limited.…”

Compliance with Dietary Guidelines and Increased Fortification Can Double Vitamin D Intake: A Simulation Study

“…Thus, the contribution of meat to vitamin D intake and status could be higher than currently estimated. Taylor et al [36] have suggested that an additional 1.7-2.9 µg or 15-30% of the EAR for vitamin D could be added to currently estimated intakes in the US if the presence of 25(OH)D in animal-based foods is taken into account. Nonetheless, due to the increased risk of chronic diseases, the recommendation is to keep intake of meat below 500 g/week [37,38].…”