This is why we shrink as we age – Health

But other age-related processes make us smaller, too. One of the most important causes is low bone density, which is thought to be caused by a decline in estrogen and testosterone with age. Vitamin D deficiency and decreased calcium absorption as we age can worsen this process, sometimes leading to a bone disease known as osteoporosis. As bones become weaker and more porous, the vertebrae that make up the spine can become compressed under our weight, leading to fractures. Surprisingly, most of these fractures are painless, which is why we usually don't notice how our spine becomes shorter over time. This bone loss occurs more frequently in postmenopausal women. Posture can also have an effect on body size. For example, if we sit hunched over in front of our computer for years, this can lead to deformation of the spine, which also makes us smaller. Paying attention to healthy sitting posture, getting up and stretching from time to time, and targeted back training are the right antidote.