Just published this month in the journal Osteoporosis International, a new study revealed that bone health was similar between vegan Buddhist nuns and omnivore women even though the vegans had much lower intakes of calcium and protein.
The study involved 105 vegan nuns and 105 omnivore women in Viet Nam. Average calcium intake was 375 mg per day for the vegans and 682 mg for the omnivores. (Some of the vegan women did use very small amounts of milk in meals.) Vegan women also had low protein intakes averaging around 35 grams per day compared to more moderate intakes of 62 grams for the omnivores.
Bone density between the two groups was similar—slightly lower in the vegans, but not to an extent that was statistically significant. Prevalence of osteoporosis was slightly higher among the vegans. Overall, there was little difference between the two groups.
Before you toss your calcium supplements out the window, though, there are a few things to keep in mind. Many factors—diet, lifestyle, and genetics—affect bone health. We can’t automatically make recommendations for western vegans based on this study. Other studies have shown bone density to be lower in vegans compared to omnivores when calcium intakes were different.
This study adds to the pile of interesting—but confusing—data we have on bone health and diet. Personally, I am still aiming for 1,000 mg of calcium per day along with lots of exercise, plenty of vitamin D and a moderate sodium intake. At least until the data are more clear and more compelling. What is clear however, is that bone health is complex; it’s not all about calcium.