From the Guidelines
The evidence regarding ketogenic diets and bone health suggests caution is warranted, as these diets may potentially have negative effects on bone mineral density and increase fracture risk in some individuals. Current research indicates that very low-carbohydrate ketogenic diets may lead to increased bone resorption and decreased bone formation, particularly when followed for extended periods 1. This concern appears more pronounced in children, adolescents, and women, especially those who are postmenopausal. The mechanism likely involves increased acid load from protein metabolism, reduced calcium absorption due to lower carbohydrate intake, and hormonal changes that occur during ketosis.
To mitigate potential bone health risks while following a ketogenic diet,
- ensure adequate calcium intake (1000-1200mg daily)
- maintain sufficient vitamin D levels (1000-2000 IU daily)
- incorporate weight-bearing exercise regularly
- consider periodic bone density monitoring if following the diet long-term. Adding non-starchy vegetables can help buffer the acid load while maintaining ketosis 1. For those with existing osteoporosis, osteopenia, or high fracture risk, a less restrictive low-carbohydrate approach rather than strict ketosis may be more appropriate for bone health preservation. It is also important to note that the effect of nutrition on bone health is complex, and while some studies suggest that vitamin D and calcium supplementation may be beneficial, others have found limited evidence to support their use in preventing fractures 1.
In terms of exercise,
- structured exercise interventions, including progressive resistance exercise training, can improve mobility and physical function in individuals who have experienced a fragility fracture
- multicomponent exercise, incorporating strength and balance training, can reduce the risk of falls in people with osteoporotic fracture 1. Overall, a comprehensive approach that includes a balanced diet, regular exercise, and careful monitoring of bone health is necessary to minimize the potential risks associated with ketogenic diets and bone health.
From the Research
Ketogenic Diet and Bone Health
- The relationship between the ketogenic diet and bone health is complex and has been studied in various research papers 2, 3, 4, 5, 6.
- A systematic review of published studies found that the ketogenic diet did not have a significant effect on bone mass density (BMD) or bone resorption 3.
- However, another study found that children treated with the ketogenic diet had low normal BMD, which may decrease further during treatment, and that monitoring of BMD is crucial 6.
- The importance of a balanced diet, including minerals, protein, and fruit and vegetables, for bone health and in the prevention of fragility fractures has been emphasized 2.
- Vitamin D and calcium play important roles in improving bone mineral density and reducing the risk of fracture, and deficiencies in these nutrients can have negative effects on bone health 4, 5.
Nutritional Factors and Bone Health
- A balanced diet with an optimal protein and calcium intake, and vitamin D sufficiency, is recommended for maintaining bone health 2.
- Dairy products are a valuable source of protein and calcium, and consuming them has been associated with a lower risk of hip fractures 2.
- A Mediterranean diet or a prudent diet has also been associated with a lower fracture risk 2.
- Vitamins A, B, C, E, and K have been found to play a role in bone health, and deficiencies in these vitamins can have negative effects on bone health 4.
Ketogenic Diet and Bone Mineral Density
- A retrospective observational cohort study found that children treated with the ketogenic diet had low normal BMD, which may decrease further during treatment 6.
- The study also found that intravenous bisphosphonate therapy may have a positive effect on BMD in patients treated with the ketogenic diet 6.
- Another study found that the ketogenic diet did not have a significant effect on bone mineral density or bone resorption 3.