X-Ray of rheumatoid arthritis in the hand

Factors affecting bone strength

What we eat and how much we move about affects how strong our bones are


High-calcium foods and drinks like cheese and milk help raise peak bone mass, a key factor in delaying the onset of osteoporosis. More than two-thirds of bone by weight is made of calcium phosphate crystals embedded in the matrix that bone cells build.

Vitamin D is important too, because it helps calcium absorption. We make most of the vitamin D we need through exposure to sunlight.

Darker skin takes more time in sunlight to make vitamin D than lighter skin, so some dark-skinned people living in temperate countries may need extra vitamin D in their diet to make up for the lack of strong sunlight.


Like muscle, bone is a living tissue that gets stronger in response to exercise. However, not all types of exercise offer the same benefits – weight-bearing exercise is best. Jumping strengthens bones more than running, for example, because it places bones under a greater load. 

Lead image:

Wellcome Images/Flickr CC BY NC


About this resource

This resource was first published in ‘Exercise, Energy and Movement’ in January 2012 and reviewed and updated in August 2016.

Cell biology, Physiology, Health, infection and disease
Exercise, Energy and Movement
Education levels:
14–16, 16–19, Continuing professional development