Vegan diets can support adequate intake of nutrients critical for bones, if fortified foods and supplements are included. That’s the key takeaway from a new study from the University of Helsinki, published in the European Journal of Nutrition.
Researchers examined children ages 2-7 and their caregivers who followed vegan, vegetarian or omnivorous diets. They found that vegans consistently used vitamin D supplements and fortified foods, leading to adequate calcium and vitamin D intakes. In fact, children on vegan diets often had higher vitamin D levels than omnivores because they consumed supplements more regularly.
“The calcium naturally occurring in plant-based foods is fairly poorly absorbed. In fact, the widespread vitamin D and calcium fortification of plant-based dairy alternatives in Finland is important for the adequate intake of these nutrients among vegans and, consequently, for their bone health,” said Docent Suvi Itkonen of the University of Helsinki.
Still, the study found differences in bone metabolism markers. Adults following vegan and vegetarian diets showed higher levels of both bone formation and resorption, which could indicate accelerated bone turnover. Among children, vegan diets were linked to higher parathyroid hormone concentrations, a marker associated with more active bone resorption. The clinical significance of these findings remains unclear, but researchers caution they may signal long-term effects on bone health.
Protein intake was generally adequate across all diet groups, though vegans and vegetarians consumed less than omnivores. Researchers noted that plant proteins differ in amino acid composition and absorption, which could also play a role in bone metabolism.
Because the study was conducted in Helsinki, where fortified vegan products are widely available and families are well informed about supplement use, the findings may not apply to populations with less access to fortified foods or lower vitamin D intake.
“People in the Helsinki Metropolitan Area live in a kind of veggie bubble,” Itkonen said. “Due to that one has to keep in mind that the findings of the study are not directly applicable to the populations of other regions or countries.”
The researchers emphasize that vegan diets, especially for children, require careful planning. Choosing calcium- and vitamin D–fortified plant milks and yogurts, and giving children a daily vitamin D supplement, are key strategies to protect bone health.
Open Access funding was provided by the University of Helsinki (including Helsinki University Central Hospital). The MIRA2 study was supported by the Signe and Ane Gyllenberg Foundation and the Päivikki and Sakari Sohlberg Foundation. This bone-related sub-study was supported by the Juho Vainio Foundation and the Foundation for Nutrition Research.