TY - JOUR
T1 - Vitamin A intake and the risk of hip fracture in postmenopausal women
T2 - The Iowa Women's Health Study
AU - Lim, L. S.
AU - Harnack, L. J.
AU - Lazovich, D.
AU - Folsom, A. R.
PY - 2004/7
Y1 - 2004/7
N2 - Excessive intake of vitamin A is postulated to have a detrimental effect on bone by inducing osteoporosis. This may lead to an increased risk of fracture, particularly in persons who are already at risk of osteoporosis. However, few studies have specifically examined the association of vitamin A intake through diet and supplement use, with fractures in a cohort of older, community-dwelling women. We prospectively followed a cohort of 34,703 postmenopausal women from the Iowa Women's Health Study to determine if high levels of vitamin A and retinol intake through food and supplement use were associated with an increased risk of hip or all fractures. A semiquantitative food frequency questionnaire was used to obtain the participants' baseline vitamin A and retinol intake. Participants were followed for a mean duration of 9.5 years for incident self-reported hip and nonhip fractures. After multivariate adjustment, it was revealed that users of supplements containing vitamin A had a 1.18-fold increased risk of incident hip fracture (n = 525) compared with nonusers (95% CI, 0.99 to 1.41), but there was no evidence of an increased risk of all fractures (n = 6,502) among supplement users. There was also no evidence of a dose-response relationship in hip fracture risk with increasing amounts of vitamin A or retinol from supplements. Furthermore, our results showed no association between vitamin A or retinol intake from food and supplements, or food only, and the risk of hip or all fractures. In conclusion, we found little evidence of an increased risk of hip or all fractures with higher intakes of vitamin A or retinol among a cohort of older, postmenopausal women.
AB - Excessive intake of vitamin A is postulated to have a detrimental effect on bone by inducing osteoporosis. This may lead to an increased risk of fracture, particularly in persons who are already at risk of osteoporosis. However, few studies have specifically examined the association of vitamin A intake through diet and supplement use, with fractures in a cohort of older, community-dwelling women. We prospectively followed a cohort of 34,703 postmenopausal women from the Iowa Women's Health Study to determine if high levels of vitamin A and retinol intake through food and supplement use were associated with an increased risk of hip or all fractures. A semiquantitative food frequency questionnaire was used to obtain the participants' baseline vitamin A and retinol intake. Participants were followed for a mean duration of 9.5 years for incident self-reported hip and nonhip fractures. After multivariate adjustment, it was revealed that users of supplements containing vitamin A had a 1.18-fold increased risk of incident hip fracture (n = 525) compared with nonusers (95% CI, 0.99 to 1.41), but there was no evidence of an increased risk of all fractures (n = 6,502) among supplement users. There was also no evidence of a dose-response relationship in hip fracture risk with increasing amounts of vitamin A or retinol from supplements. Furthermore, our results showed no association between vitamin A or retinol intake from food and supplements, or food only, and the risk of hip or all fractures. In conclusion, we found little evidence of an increased risk of hip or all fractures with higher intakes of vitamin A or retinol among a cohort of older, postmenopausal women.
KW - Fracture
KW - Hip fracture
KW - Osteoporosis
KW - Postmenopause
KW - Retinol
KW - Vitamin A
UR - http://www.scopus.com/inward/record.url?scp=3142629989&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=3142629989&partnerID=8YFLogxK
U2 - 10.1007/s00198-003-1577-y
DO - 10.1007/s00198-003-1577-y
M3 - Article
C2 - 14760518
AN - SCOPUS:3142629989
SN - 0937-941X
VL - 15
SP - 552
EP - 559
JO - Osteoporosis International
JF - Osteoporosis International
IS - 7
ER -