How to Measure Bone Density

Close-up image of Jules Walters

Jules Walters • Nov. 23, 2022

There are many reasons to celebrate living past menopause. There is more time for ourselves and those we love, and we no longer have to prove ourselves to anyone.

But one of the biological drawbacks of living post-menopause is that our bones are thinning. If I had to choose just one supplement for women over 50, it would be calcium. Read on to find out why.

Having your back

Once our estrogen levels drop, it’s estimated we’re losing around TWO per cent of our bone mass EACH YEAR, according to research published in The New England Journal of Medicine back in 2003. Since then, multiple studies have confirmed this significant loss. That’s a lot, and not to be shrugged off. Please pay attention to this.

Research shows that women may have lost up to 20% of their bones by the time they finish menopause.

I have friends in their 50s, who are starting to stumble and suffer bone fractures. My mum, who is a healthy 87, has many friends who have had hip replacements, broken arms and broken wrists.

So, listen up! There is something you can do about it.

Establish your base line

I highly recommend that you know your base line for bone density. How good are your bones now? A reliable way to check your bone strength is through an imaging text called a DEXA or DXA scan. It uses low levels of x-rays to see what’s happening under your skin. The acronym is short for dual energy x-ray absorptiometry.

The test will come back with two scores: a T-score and a Z-score.

A T-score compares your bones to a healthy, 30-year-old. It will present the score as a standard deviation. In other words, it calculates how much you differ from the average. One standard difference is equal to a 10-12% difference in bone mass. So if your T-score is -1, then you have 10-12% less bone density than someone aged 30. 

The World Health Organization defines osteopenia, which comes before osteoporosis, as a T-score between -1.0 and -2.5 deviations below normal. So: if your T-score is greater than -1.0, it’s time to have a conversation with your doctor. 

A Z-score compares your bone density to the average of people your own age and gender.

Please request both your Z-score and your T-score, so you can put in place a plan based on the results.

Why doesn’t my doctor mention bone loss?

Remember doctors are trained to treat sickness – not prevent it – so prevention is personal. It’s up to you.

The North American Menopause Society (NAMS) says osteoporosis can be a serious health threat for women after menopause.

To keep your bones healthy, the Bone Health and Osteoporosis Foundation recommends 1,200 mg of calcium per day for women aged 50 and older. 

You CAN find calcium in foods, particularly dairy products like milk, yogurt and cheese. Dark-green leafy vegetables contain calcium, particularly collard greens, as does canned salmon. 

It’s reasonable to plan that you’ll get half your calcium from a healthy diet. For example, a 200 ml pot of yogurt contains about 260 mg calcium; a cup of milk has 305 mg. 

So to get at least 1,200mg a day, consider calcium supplements for the 600 mg of calcium you’re unlikely to get from your diet. Ideally, choose a calcium supplement with vitamins D and K to ensure the calcium gets out of your blood and into your bones.

In 2021, the North American Menopause Society reviewed the evidence for the management of osteoporosis in post-menopausal women. It found that there is no single or optimal management strategy for osteoporosis. 

So, if you’re post-menopause, get a bone scan. See where you are in terms of T and Z scores. Then talk to your doctor. If your doctor doesn’t take your bone scan seriously, get another doctor!

“Menopause is not a disease that needs some kind of a cure. It’s a natural transition, to be approached as a new type of freedom and personal power.”

Dr Anna Cabeca, The Hormone Fix

Living bones

We’re used to thinking of bones as pretty static elements of our body, a bit like the scaffolding holding everything together. However, bones are actually living tissue with blood vessels and specialized cells, like stem cells. And most of our adult skeleton is replaced every 10 years.

Our bone matrix is about 94% collagen; an important protein. The hardness is due to a crystalline structure of calcium and phosphate. Like a garden, it needs your attention.

Fractures are most likely to happen in our arms, shoulders, hips and spine. Statistics show that women suffer a lot more fractures than men, as we age. It’s that loss of estrogen again.