In Australia, a woman's calcium recommendation goes up at 51. It moves from 1,000mg a day to 1,300mg, and it moves on a birthday.
Your bones do not work to that timetable. They work to your last period.
The three years that matter most
Bone density does not decline steadily from midlife onwards. It falls slowly, then it falls fast, then it slows again.
The fast phase begins about a year before your final period and runs for roughly two years afterwards. Researchers call that window the transmenopause, and during it bone density drops by around 2% a year, with the spine losing faster than the hip.
The scale of it is easier to see over a decade. Across ten years spanning the menopause transition, women in the SWAN study lost 10.6% of their spine bone density. Of that, 7.4% went during those three years.
So roughly two thirds of a decade's bone loss happens in about a third of the time.
Why the timing catches people out
The average age of the final period in Australia is around 51, which is why the guidelines sit there. But that is an average, and the fast phase starts a year before it.
For a woman whose periods stop at 48, the window opens at 47. For anyone with early menopause, earlier again. And nobody knows their final period is their final period until a year has gone by, which means most women are already inside the window before it can be named.
It runs the other way too. If your periods carry on into your mid fifties, the guideline changed at 51 and your window has not opened yet.
If you go through menopause later
There is a reassuring finding here. Women who reach menopause later tend to have higher bone density afterwards and a lower risk of fracture, because they have had more years of oestrogen behind them.
The fast phase still comes. It just arrives later, and from a better starting point. So the same three years matter, they are simply not the three years the guidelines are pointing at.
Which answers the question this series is asking. Feeling like something shifted in your late forties is not you imagining it, and it is not simply getting older. There is a specific, measurable, time-limited thing happening.
Why it matters beyond the number
Women who lose more bone during that window go on to have more fractures, and that holds true regardless of how much bone density they started with.
Which makes it a different situation to a slow decline you can address later. Starting from a good baseline helps, but it does not protect you from a fast loss phase.
What actually helps
Calcium, and from food where possible. Four serves a day is the guidance after 50, and dairy is not the only way to get there.
Vitamin D, because calcium is not much use without it. In southern Australia winter is when levels are lowest, and a test through your GP is the only way to know where yours sit.
Resistance training, which is the part most often left out. Bone responds to load, so lifting something heavy enough to be difficult builds density in a way that walking does not.
Protein, because muscle pulls on bone and the two decline together. Breakfast is usually where it runs short.
None of it requires waiting for a birthday.
Where Greenher fits
Greenher Daily carries 584mg of calcium per serve. For a woman over 51 that is a little under half a day's requirement, and calcium supports normal bone maintenance.
It also carries vitamin D, at 2.5 micrograms. That is a quarter of what you need after 51, so treat it as a contribution rather than a solution. If you have reason to think your vitamin D is low, a test is the answer rather than a scoop of anything.
Every nutrient and amount is on our formula page, calculated against women's requirements rather than an average adult.
Raise it with your GP if
You have had an early menopause, a fracture from a minor fall, a family history of osteoporosis, long-term steroid use, coeliac disease, or a low body weight. A bone density scan is a reasonable thing to ask about rather than to wait for.
The takeaway: The calcium recommendation changes at 51, but bone loss is anchored to your final period rather than a birthday. The fast phase runs from about a year before to two years after, and roughly two thirds of a decade's loss happens in it. Losing more during that window predicts fracture regardless of your starting point, so the useful time to act is before it closes.
Part of Is This Just Getting Older?
This post is part of a month-long collaboration with seven other women working in midlife health, and there is a prize pack to enter. Everything you need to enter is on one page. Entries close 18 October.
The science behind this post:
- Greendale GA, Sowers M, Han W, et al. (2012). Bone mineral density loss in relation to the final menstrual period in a multiethnic cohort: results from the Study of Women's Health Across the Nation (SWAN). Journal of Bone and Mineral Research. Rates of loss were greatest from 1 year before to 2 years after the final menstrual period. Cumulative 10-year lumbar spine loss was 10.6%, of which 7.38% occurred during the transmenopause. Read it here
- Study of Women's Health Across the Nation. Bone Health over the Menopause Transition fact sheet. During the fast loss phase, bone density declines on average about 2% per year, with greater declines in the spine than the hip. Read it here
- Shieh A, Karlamangla AS, Huang MH, Han W, Greendale GA (2021). Faster lumbar spine bone loss in midlife predicts subsequent fracture independent of starting bone mineral density. Journal of Clinical Endocrinology and Metabolism, 106(7). Read it here
- Shieh A, Ruppert KM, Greendale GA, et al. (2022). Associations of age at menopause with postmenopausal bone mineral density and fracture risk in women. Journal of Clinical Endocrinology and Metabolism, 107(2). Earlier menopause is associated with lower postmenopausal bone mineral density and higher fracture risk. Read it here
- National Health and Medical Research Council (2006). Nutrient Reference Values for Australia and New Zealand. Where the calcium target rising from 1,000mg to 1,300mg at 51, and the vitamin D target of 10 micrograms after 51, come from. Calcium | Vitamin D