The health and strength of bones is largely determined by the amount of minerals, particularly calcium and magnesium, consumed; until the age of 35 when peak bone mass is achieved. As we get older the rate of bone breakdown increases and bone density decreases. Ensuring sufficient calcium in the diet is especially important for young children and women since physical changes that occur at the time of the menopause impact on bone mineral. Calcium supplement products, particularly those also including vitamin D, are often advised to ensure optimal intake of calcium for the maintenance of bone health. However, the evidence tends to point towards a higher density but not necessarily a higher strength. There is some evidence, particularly from epidemiological reviews, that the co-factors, in the bone protein construction, that vitamin D and vitamin K2 are vital along with the minerals magnesium, zinc and boron. These minerals are more likely to be sub-optimal in many diets. Populations whose lives, skin colour or locations result in insufficient sun exposure and thereby less vitamin D are more prone to osteoporosis.