Vegan Diet Could Affect Bone Health, Study Suggests

A vegan diet has been associated with many health benefits, including high vitamin and fiber intake and healthy cholesterol levels. But a recent study suggests that going strictly plant-based may have some potential drawbacks to be wary of. 

Research from the German Federal Institute for Risk Assessment (BfR) published in the journal Nutrients found that people on a vegan diet had lower ultrasound values (based on a heel bone measurement), which indicates poorer bone health. A total of 72 people took part in the study – 36 vegans and 36 people who on a mixed-food diet (ie part plants, part animal produce). 

The results of this study do not imply that being vegan is in any way an unhealthy choice, it merely emphasizes the importance of paying attention to nutrient intake if you or a loved one follow a vegan lifestyle.

About the Study

“Our biggest takeaway is that your choice of diet may be related to your bone health,” says study author Dr. Juliane Menzel, from the Institute for Social Medicine, Epidemiology and Health Economics at Charité – Universitätsmedizin Berlin.

"We were able to identify an exploratory pattern of twelve biomarkers that play an important role in bone health from 28 nutrition- and bone-relevant parameters from blood or urine," Dr. Menzel says. "This indicates a complex interplay between nutrients, which implies that no single element of a diet can provide the complete picture of dietary effects on bone health."  

The results of this study are in line with other evidence. For instance, a systematic review and meta-analysis from 2019 (including 20 studies and 37,134 participants) showed that vegetarian and vegan diets were associated with lower bone mineral density (BMD), compared to omnivores. The association was more pronounced in vegans compared to vegetarians, and vegans had a higher fracture risk than omnivores.

Another study from 2020 notes that non-meat eaters, especially vegans, had higher risks of either total or some site-specific fractures.

Looking After Our Bones

It can be difficult to get all the nutrients needed for bone (and other) health from a vegan diet. "This small study not only shows a difference in nutrient status for a number of nutrients, but also shows lower mineralization in the heel bone through the use of ultrasound bone scans," says Julie Miller Jones, PhD, LN, CNS, RD, an emeritus professor of nutrition at St. Catherine University in St. Paul, MN, and a member of the Grain Foods Foundation's Scientific Advisory Board. 

She explains that lower bone density in the heel is associated with lower bone density in the hip and greater risk of hip fracture – a major cause of death and debility.

"One out of three adults age 50 and over who suffer a hip fracture will die within a year," Miller adds. "The statistics become grimmer as years advance and may mean loss of physical function and independence."

Maximum bone mass occurs at around age 25, but you can help to slow the subsequent bone loss with bone-jarring exercise like running and walking and the right diet, Miller says. This is important, she notes, because statistics show that those most likely to be vegan are ages 18-40. And after menopause, women experience an abrupt loss of bone mass. 

Nutrients For Bone Health

Iron, calcium, and vitamin D are the most important nutrients for bone health, says Vanessa Rissetto, MS, RD, CDN, co-founder of Culina Health. "It’s the lower intake of calcium and protein that puts vegans at a higher risk for bone deficiency than meat eaters," Rissetto explains. 

To make up for what they're missing from the foods they eat, plant-based eaters can take dietary supplements. Rissetto recommends taking supplementary vitamin D, calcium, and iron. "I also recommend an increase of dark leafy greens, plus ample protein from beans, legumes, etc," she adds.

Additionally, Miller points out that vegan diets are generally low in riboflavin, B6 and B12; zinc, iodine, and magnesium, plus long-chain omega-3 fatty acids such as those found in fish. She recommends a B12 supplement or fortified cereals, which are made with refined grains that include essential vitamins and minerals.

"Vegan diets should be appropriately organized to maintain a nutritional balance, careful planning of a rich and varied diet, mostly with the addition of supplements, eg vitamin B12," Dr. Menzel says. "Therefore, vegans should inform themselves thoroughly, with the help of qualified nutritionists if necessary."