|Older people worried about osteoporosis should pay attention to the SPF (sunscreen protection factor) on sunscreens.
Because the body cannot absorb sufficient calcium without vitamin D, a vitamin D deficiency can be a major factor in bone loss. The skin makes Vitamin D when it is exposed to sunlight. Sunscreens with an SPF above eight, block the ultraviolet wavelengths that convert vitamin D into the form needed by the body.
Since the body's ability to produce vitamin D from sunlight declines with age, older people are particularly at risk.