ASBMR 2014 Presentation: Vitamin K(1) supplements failed to improve BMD in postmenopausal osteopenia (Huang ZB, et al.)
Women with osteopenia after menopause demonstrating low vitamin K1 concentrations did not improve bone mineral density (BMD) with long-term vitamin K1 supplements for the deficiency, according to research presented at the American Society for Bone and Mineral Research (ASBMR) 2014 Annual Meeting entitled “Vitamin K supplements failed to improve BMD in postmenopausal osteopenia”.
“Overall, vitamin K1 supplementation does not reduce bone loss in postmenopausal women with low bone mass, even among those who have low levels of serum vitamin K1,” Maryam S. Hamidi, PhD, of the University Health Network in Toronto, told Endocrine Today.
Dr. Hamidi, along with Angela M. Cheung, MD, PhD, also of the University Health Network, and colleagues analyzed data from 159 women in their postmenopausal years with baseline fasting serum vitamin K1 concentrations ≤1 nmol/L; patients were from the ECKO trial.
The mean age of the patients (94% white, 19% apolipoprotein E4 carriers) was 59 ± 7 years and mean BMI was 25.6 ± 4.2 kg/m2. At baseline, median serum vitamin K1 concentration was 0.6 nmol/L (interquartile range, 0-0.8), and 31% of women had concentrations of zero.
The women received either 5 mg vitamin K1 (n=80) or placebo (n=79) once daily. The researchers advised the women to maintain a total daily intake of 1,500 mg calcium and 800 IU vitamin D throughout the trial.
BMD changes were evaluated at 2 years in four sites: lumbar spine, femoral neck, total hip and ultradistal radius. Changes in bone turnover were assessed based on 2-year change in osteocalcin, C-terminal telopeptide, and percentage of undercarboxylated osteocalcin. Two-sample t tests were used to determine all outcomes.
At 24 months, median serum vitamin K1 with treatment was 17.4 nmol/L (interquartile range, 9-27.9) vs. 1 nmol/L (interquartile range, 0.5-1.8) with placebo. A significant decrease was seen in serum levels of total osteocalcin and percentage of undercarboxylated osteocalcin with treatment vs. placebo.
“This is exactly what we would expect with vitamin K supplementation,” Dr. Hamidi said. No significant differences were seen between groups for any of the BMD outcomes or for C-terminal telopeptide.
“We do not recommend the use of vitamin K1 supplementation for prevention of bone loss in postmenopausal women who have low bone mass,” Dr. Hamidi said. “However, healthy diets that include green plant foods, which are good sources of vitamin K1, may be beneficial for bone health.”
Dr. Katarzyna Maresz, president of the International Science and Health Foundation, was equally unsurprised by the results presented in the abstract; however, she notes that the presentation’s title is misleading. “It has already been shown that Vitamin K1 is primarily taken up by the liver, leaving little for the rest of the body’s systems, including the bones and the heart,” she said, noting that as the researchers advised the women to maintain a total daily intake of 1,500 mg calcium and 800 IU vitamin D throughout the trial, Vitamin K2 would have proven much more beneficial for the subjects. “The Knappen et al. study that published in Osteoporosis International showed that a daily dose of 180 mcg significantly decreases age-related loss in bone mass and thereby exerts improvements in bone strength.”
Reference: Hamidi M. Abstract #1078. Presented at: ASBMR 2014 Annual Meeting; Sept. 12-15, 2014; Houston, TX.