TY - JOUR
T1 - Vitamin D status in postmenopausal women living at higher latitudes in the UK in relation to bone health, overweight, sunlight exposure and dietary vitamin D
AU - Macdonald, Helen M.
AU - Mavroeidi, Alexandra
AU - Barr, Rebecca J.
AU - Black, Alison J.
AU - Fraser, William D.
AU - Reid, David M.
N1 - Funding Information:
The authors wish to thank Colin Driscoll for providing data on sunlight intensity weighting, Caroline Bolton Smith for the sunlight exposure questionnaire and Brian Diffey for advice on calculating the sunshine exposure score. We are indebted to the staff at the Osteoporosis Research Unit and to all the women who kindly took part. The study was part funded by Grampian Osteoporosis Trust and the UK Foods Standards Agency. Any views expressed are the authors' own. Thanks to Dr N Hoyle (Roche) for supplying the P1NP kits.
PY - 2008/5
Y1 - 2008/5
N2 - For 5 months a year the UK has insufficient sunlight for cutaneous synthesis of vitamin D and winter requirements are met from stores made the previous summer. Although there are few natural dietary sources, dietary intake may help maintain vitamin D status. We investigated the relationship between 25-hydroxyvitamin D (25(OH)D), bone health, overweight, sunlight exposure and dietary vitamin D in 3113 women (age 54.8 [SD 2.3] years) living at latitude 57°N between 1998-2000. Serum 25(OH)D was measured by high performance liquid chromatography (HPLC), dietary intakes (food frequency questionnaire, n = 2598), sunlight exposure (questionnaire, n = 2402) and bone markers were assessed. Bone mineral density (BMD) was measured by dual x-ray absorptiometry in all women at the sampling visit and 6 years before. Seasonal variation in 25(OH)D was not substantial with a peak in the autumn (23.7 [9.9] ng/ml) and a nadir in spring (19.7 [7.6] ng/ml). Daily intake of vitamin D was 4.2 [2.5] μg from food only and 5.8 [4.0] μg including vitamin D from cod liver oil and multivitamins. The latter was associated with 25(OH)D at each season whereas vitamin D simply from food was associated with 25(OH)D in winter and spring only. Sunlight exposure was associated with 25(OH)D in summer and autumn. 25(OH)D was negatively associated with increased bone resorption and bone loss (P < 0.05) remaining significant after adjustment for confounders (age, weight, height, menopausal status/HRT use, physical activity and socio-economic status). Using an insufficiency cut-off of < 28 ng/ml 25(OH)D, showed lower concentrations of bone resorption markers in the upper category (fDPD/Cr 5.1 [1.7] nmol/mmol compared to 5.3 [2.1] nmol/mmol, P = 0.03) and no difference in BMD or bone loss. 25(OH)D was lower (P < 0.01) and parathyroid hormone higher (P < 0.01) in the top quintile of body mass index. In conclusion, low vitamin D status is associated with greater bone turnover, bone loss and obesity. Diet appears to attenuate the seasonal variation of vitamin D status in early postmenopausal women at northerly latitude where quality of sunlight for production of vitamin D is diminished.
AB - For 5 months a year the UK has insufficient sunlight for cutaneous synthesis of vitamin D and winter requirements are met from stores made the previous summer. Although there are few natural dietary sources, dietary intake may help maintain vitamin D status. We investigated the relationship between 25-hydroxyvitamin D (25(OH)D), bone health, overweight, sunlight exposure and dietary vitamin D in 3113 women (age 54.8 [SD 2.3] years) living at latitude 57°N between 1998-2000. Serum 25(OH)D was measured by high performance liquid chromatography (HPLC), dietary intakes (food frequency questionnaire, n = 2598), sunlight exposure (questionnaire, n = 2402) and bone markers were assessed. Bone mineral density (BMD) was measured by dual x-ray absorptiometry in all women at the sampling visit and 6 years before. Seasonal variation in 25(OH)D was not substantial with a peak in the autumn (23.7 [9.9] ng/ml) and a nadir in spring (19.7 [7.6] ng/ml). Daily intake of vitamin D was 4.2 [2.5] μg from food only and 5.8 [4.0] μg including vitamin D from cod liver oil and multivitamins. The latter was associated with 25(OH)D at each season whereas vitamin D simply from food was associated with 25(OH)D in winter and spring only. Sunlight exposure was associated with 25(OH)D in summer and autumn. 25(OH)D was negatively associated with increased bone resorption and bone loss (P < 0.05) remaining significant after adjustment for confounders (age, weight, height, menopausal status/HRT use, physical activity and socio-economic status). Using an insufficiency cut-off of < 28 ng/ml 25(OH)D, showed lower concentrations of bone resorption markers in the upper category (fDPD/Cr 5.1 [1.7] nmol/mmol compared to 5.3 [2.1] nmol/mmol, P = 0.03) and no difference in BMD or bone loss. 25(OH)D was lower (P < 0.01) and parathyroid hormone higher (P < 0.01) in the top quintile of body mass index. In conclusion, low vitamin D status is associated with greater bone turnover, bone loss and obesity. Diet appears to attenuate the seasonal variation of vitamin D status in early postmenopausal women at northerly latitude where quality of sunlight for production of vitamin D is diminished.
KW - 25-hydroxy vitamin D
KW - Bone loss
KW - Dietary vitamin D
KW - Postmenopausal women
KW - Sunlight exposure
UR - http://www.scopus.com/inward/record.url?scp=41949086909&partnerID=8YFLogxK
U2 - 10.1016/j.bone.2008.01.011
DO - 10.1016/j.bone.2008.01.011
M3 - Article
C2 - 18329355
AN - SCOPUS:41949086909
SN - 8756-3282
VL - 42
SP - 996
EP - 1003
JO - Bone
JF - Bone
IS - 5
ER -