D-FINES

Summary

Currently, in the UK, there is no DRV (dietary reference value) for vitamin D.

This is because, until now, there has been a belief that exposure of the skin to UV B rays contained in sunlight is sufficient. We do know that vitamin D is derived from two sources: the skin (endogenous) and the diet (exogenous). We do not know what the relative significance of both dietary sources and sunlight exposure on vitamin D status is.

The question needs to be urgently addressed given the findings of the recent NDNS surveys (4-18 years; 19-65 years and 65 years +) and Hypponen and Powers 2007 Study showing vitamin D insufficiency is a problem in the UK.

Project Status : November 2008

The project focuses on the interaction between diet and sunlight exposure on vitamin D status and functional markers of bone health in premenopausal and postmenopausal Caucasian and Asian women living in Southern England at (51°N).

The project data collection is now complete. A total of 293 women completed 4 measurements in 1 year (Summer 06; Autumn 06; Winter 06/07; Spring 07).

The D-FINES team secured further funding from the FSA to repeat the measurements in Spring 2008.

Analysis of all the data collected is currently underway and results will be released in early 2009.

Project Objectives

Our key objectives are:

1. To determine the percentage contribution of diet and sunlight exposure on vitamin D status/functional markers of calcium metabolism in each of the four seasons in Caucasian and Asian pre- and postmenopausal women and directly compare results of postmenopausal women living in a Southern and Northern climate.
2. To investigate the effect of ethnicity on the relative contribution of diet and sunlight to vitamin D status/functional markers to determine if diet plays a more significant role in determining vitamin D status in Asian than Caucasian populations.
3. To investigate which foods/food groups are the major contributors to dietary vitamin D intake and determine the commonality of findings between ethnic groups and geographical location.
4. To determine if poor dietary intake of vitamin D/low sunlight exposure, hence poor vitamin D status has a detrimental effect on functional markers of bone health, namely BMD, bone ultrasound, bone turnover and establish whether this effect is more pronounced in older women compared with younger women.

Results and Findings

Preliminary results of the D-FINES study were presented at the 2007 Nutrition Society Conference held at the University of Nottingham and will be published in the Proceedings of the Nutrition Society shortly.

Lanham-New SA., Lee PA., Wong M., Sui C., Starkey S., Berry J., Griffin B. Association between dietary vitamin D intake and serum lipid profiles in Asian and Caucasian UK women: preliminary results from the Vitamin D, Food Intake, Nutrition and Exposure to Sunlight in Southern England (D-FINES) Study. Proceedings of the Nutrition Society 2008 (In Press).

Lee P., Tan L., David D., Nurmi-Lawton JA., Lee WTK and Lanham-New SA. Intakes of key bone health nutrients in Caucasian and Asian women living in Southern England: baseline results from the Vitamin D, Food Intake, Nutrition and Exposure to Sunlight in Southern England (D-FINES) Study. Proceedings of the Nutrition Society 2008 (In Press).

Hanjra F., Lee PA., Nurmi-Lawton J., Lee WTK., Gray R., Cardew P., Duckworth A., Berry J., Patel S. and Lanham-New SA. Effect of ethnicity, season and age on axial and peripheral bone mineral density: results from the Vitamin D, Food Intake, Nutrition and Exposure to Sunlight in Southern England (D-FINES) Study. Proceedings of the Nutrition Society 2008 (In Press).

Engel B., Lee PA., Gray RES., Patel S., Duckworth A., Cardew P., Lanham-New SA. Impact of ethnicity and season on body composition: results from the D-FINES study. Proceedings of the Nutrition Society 2008 (In Press).