Does a vegetarian diet weaken your bones?
A vegetarian diet does not automatically weaken your bones, but as a vegan you need to pay extra attention to calcium and vitamin B12. Ensure adequate supplementation of both and the increased fracture risk can largely be prevented.
Vegans have, on average, lower bone density than omnivores, but whether this also leads to more fractures depends strongly on calcium intake. One review concludes that vegans with adequate calcium intake do not face a higher fracture risk. Those who structurally consume too little calcium, however, do have an increased risk of osteoporotic fractures. Vitamin B12 deficiency, for which vegans already need supplementation regardless, can further undermine bone health.
The picture varies across studies. Research in postmenopausal women in Taiwan found that long-term vegans exceeded the critical bone density threshold of the lumbar spine nearly 2.5 times more often, and had hip osteopenia nearly 4 times more often. Older Chinese vegetarian women had significantly lower hip bone density than omnivores. On the other hand, a large Taiwanese study of 1,865 people found no statistically significant difference in bone density or osteoporosis rates between vegetarians and non-vegetarians. And Vietnamese postmenopausal women who had lived as vegans their entire lives differed barely from omnivores in bone density of the spine, hip, or total body, despite a considerably lower calcium and protein intake.
An explanation for the contradictory results is offered by NHANES data from the US. Vegetarians weigh less on average, and lower body weight in itself already means less mechanical load on the bones, resulting in lower bone density. After correcting for this, the difference at the hip disappeared entirely; for the lumbar spine, a small but measurable difference remained.
Lacto-ovo-vegetarians (who do eat dairy and eggs) fare more favourably. In a long-term study of women aged 80, they had experienced 18% bone loss, compared with 35% in meat-eaters. This difference is linked to a more favourable calcium-to-phosphorus ratio and less acid-forming food in the vegetarian diet.
In practical terms, for lacto-ovo-vegetarians the available research does not point to worsening bones. For vegans the picture is more nuanced. Adequate calcium (from fortified foods or a supplement) and vitamin B12 are indispensable. Also pay attention to factors such as oxalic acid and phytic acid in plant-based foods, which can reduce calcium absorption.
All sources are observational studies or (non-systematic) reviews, often conducted in specific populations (postmenopausal Asian women, Buddhist nuns). No randomised trials are available. Causality cannot be established.
Is eating plant-based bad for your bones?
Eating strictly vegan is associated with lower bone density, but if you adequately supplement calcium and vitamin D, the elevated fracture risk largely disappears. As a vegan, also pay attention to vitamin B12, and discuss any supplement use with your GP or dietitian.
Does drinking a lot of alcohol weaken your bones?
Chronic heavy drinking demonstrably weakens your bones and substantially raises the risk of a hip fracture; for your bones there is no safe level above two drinks per day.
Does taking cortisone long-term weaken your bones?
Long-term cortisone use demonstrably weakens your bones; if you use it long-term, it is wise to discuss with your doctor whether you are a candidate for bisphosphonates as a protective measure.
Can having too little body fat damage your bones?
Too little fat can damage your bones, but muscle mass and the location of fat matter at least as much. If you have concerns about bone health in combination with low body fat, discuss this with your general practitioner or sports medicine physician.
Do you really need calcium supplements for strong bones?
Whether you need calcium supplements depends strongly on your age and circumstances: for young, healthy women there is no evidence of benefit, while people over 50 may benefit from calcium plus vitamin D, provided the increased risk of kidney stones is taken into account.
Stronger bones and strength training -- does it help?
Strength training measurably improves bone density, although the effect remains modest. For the strongest results, high-intensity training under supervision is recommended, even if you already have low bone mass.