Health
Does veganism weaken bones?
Short answer
Not by definition. Risk rises when calcium, vitamin D, protein and mechanical loading (movement) are missing. A vegan with fortified plant milk, tofu and walking is not doomed to osteoporosis.
Aim for about 700–1000 mg calcium a day from fortified drinks, calcium-set tofu, tahini, brassicas and mineral-rich water. Vitamin D in a Polish winter practically requires a supplement for everyone.
Population studies are mixed because many older vegan cohorts ate little calcium. That is an argument for planning, not against veganism.