Plant-based diets could pose bone health risks without adequate calcium and vitamin D

Credit: Unsplash+

Recent research from the University of Helsinki warns that adopting a plant-based diet may compromise bone health if not balanced with sufficient calcium and vitamin D intake.

Published in The Journal of Nutrition, the study conducted by Suvi T Itkonen and colleagues highlights the potential risks of transitioning from animal-based proteins to plant-based sources.

Study Design

The research involved 136 adults who were asked to follow one of three study diets for a period of 12 weeks:

  • Diet 1: 70% animal-based protein, 30% plant-based protein
  • Diet 2: 50% animal-based protein, 50% plant-based protein
  • Diet 3: 30% animal-based protein, 70% plant-based protein

Animal-based proteins were partially replaced with a variety of plant-based proteins, including legumes, nuts, seeds, and cereals.

Fluid dairy products, fortified with vitamin D in Finland, were also partially replaced with plant-based drinks that were not fortified with calcium or vitamin D.

Key Findings

The researchers observed that both bone formation and resorption increased when animal protein was substituted with plant protein. Increased bone resorption could, in the long run, be detrimental to bone health.

Vegetarians were found to have a greater risk of bone fractures over an 18-year follow-up period compared to those who consumed a mixed diet.

The changes in bone metabolism were likely due to the reduced intake of dairy products, which resulted in lower levels of calcium and vitamin D.

Implications for Dietary Choices

While plant-based diets have been lauded for their numerous health benefits, including better blood sugar control and lower risk of heart disease, these findings stress the importance of ensuring adequate calcium and vitamin D intake when adopting such diets.

Recommendations for Adequate Nutrient Intake

For those considering a shift to a plant-based diet, it is critical to take into account the nutritional elements that could be compromised:

Ensure the consumption of fortified plant-based milks or supplements to meet the calcium and vitamin D requirements.

For vitamin D, the recommended daily intake for adults is 10 micrograms, including intake from both food and supplements.


Although plant-based diets offer numerous health advantages, this study serves as a cautionary note on the importance of balanced nutrition.

Specifically, anyone considering such a diet should pay close attention to their calcium and vitamin D intake to maintain bone health.

Further research is needed to fully understand the long-term effects of plant-based diets on bone health.

Follow us on Twitter for more articles about this topic.

Copyright © 2023 Scientific Diet. All rights reserved.