Hamidi MS et al. – The authors hypothesize that gamma–tocopherol may uncouple bone turnover, resulting in more bone formation than resorption. Vitamin E supplements in the form of alpha–tocopherol suppress serum gamma–tocopherol levels and may have negative effects on bone formation.Methods
- They examined the associations between dietary and total (diet and supplements) alpha–tocopherol intake, serum alpha–tocopherol and gamma–tocopherol levels and their ratio, and bone turnover markers (BTMs) among postmenopausal women aged ≥45 years.
- They used cross–sectional data from the National Health and Nutrition Examination Survey 1999–2002.
- Multiple regression models with adjustments for relevant confounders were used to examine the associations between intake and serum levels of tocopherols, and serum bone–specific alkaline phosphatase (BAP), a biomarker of bone formation, and urinary N–telopeptides/creatinine (uNTx/Cr), a biomarker of bone resorption.
- The study sample included 497 postmenopausal women who were not taking estrogen, steroids, or osteoporosis medications, were free from kidney and liver disease, cancer, and rheumatoid arthritis, and were fasting >9 hours prior to examination.
- Participants had a mean age of 65.5 ± 0.6 years and over 45% used vitamin E (alpha–tocopherol) supplements in the past month.
- Vitamin E supplement users had significantly lower serum gamma–tocopherol, higher serum alpha–tocopherol levels, and higher ratio of serum alpha–tocopherol to gamma–tocopherol than nonusers.
- High serum gamma–tocopherol levels and low ratio of serum alpha–tocopherol to gamma–tocopherol were associated with increased BAP levels (p < 0.01 for both).
- There were no associations between any of the vitamin E variables and uNTx/Cr.