Vitamin K Builds Bones
By Anthony Almada, M.S.

Osteoporosis concerns are on the rise as female babyboomers enter menopause and postmenopause. Calcium is, of course, a priority in keeping brittle bones at bay, and generally, vitamin D has been considered the vitamin compatriot of calcium. However, vitamin K is equally efficacious.

Newer research focuses on its role in bone protein metabolism: Among 335 men and 553 women, average age 75, those with the highest vitamin K intakes (about 250 mcg per day compared to the recommended intake of about 75 mcg per day) were associated with a threefold reduction in hip-fracture risk. Among 72,237 women in the well-known Nurses Health Study—approximate average age 57, with about half being postmenopausal—those with intakes above approximately 109 mcg per day had a lower risk of hip fracture over a 10-year period, including women who had never previously used estrogens.

What was the primary dietary vitamin K source in this study? Perhaps surprisingly, iceberg and romaine lettuces. The best food sources of vitamin K include green vegetables like parsley, brussels sprouts, spinach and broccoli and the fermented soybean product, natto.

Nutrition and exercise biochemist Anthony Almada, M.S. has collaborated on more than 45 university-based studies and is founder and chief scientific officer of IMAGINutrition.