(Updated 10/2026)
By: Joy Stephenson-Laws, JD, Founder
Most women approaching or past menopause have been told the same two things about protecting their bones: take calcium and take vitamin D. The advice is so common that many women follow it by reflex. It leaves out two parts of what bone needs: the other nutrients that work with calcium, and the physical load that signals bone to stay strong. There is also evidence that calcium taken as a supplement may carry a small heart risk.
Bone is living tissue. Cells break it down and rebuild it all the time, in response to both chemical and mechanical signals. Calcium and vitamin D cover only part of the chemical side. Here is the rest.
How bone is rebuilt
Two kinds of cells keep bone in turnover. Osteoclasts break down old bone, and osteoblasts build new bone in its place. In young adults the two stay roughly in balance. When estrogen falls at menopause, breakdown speeds up and building does not keep pace, so bone is lost.
The timing has been measured. The Study of Women's Health Across the Nation (SWAN) followed about 1,900 women through menopause. Bone loss sped up in the late perimenopause and continued at a similar pace in the first years after menopause (Finkelstein et al., 2008). Loss began about a year before the final menstrual period and slowed, without stopping, about two years after it. Researchers estimated that over the ten years surrounding the final menstrual period, bone density fell by about 10.6% in the lower spine and 9.1% at the femoral neck, the top of the thigh bone at the hip (Greendale et al., 2012).
So a woman in her 60s has usually already lost a measurable share of her bone. Rebuilding bone at that age is hard and depends on her fracture risk, her treatment and her training. The practical goals are to slow further loss and to keep her strength and balance. Two kinds of action serve those goals, and they work together.
The nutrients that work with calcium
Calcium is the main mineral in bone, and bone needs other nutrients to use it.
Magnesium. The enzyme that converts vitamin D into its active form needs magnesium, and magnesium deficiency is very common in older people (Castiglioni et al., 2013). In national survey data from 2005–2006, almost half of Americans (48%) got less than the required amount of magnesium from food (Rosanoff et al., 2012). That figure measures diet; it does not show that half of Americans are deficient. Studies in people have linked higher magnesium intake and higher blood magnesium to higher bone density. More is not always better. The same review reports that in the Women's Health Initiative, women with the highest magnesium intake had the most wrist fractures, and it links both low and high magnesium to bone problems (Castiglioni et al., 2013).
Vitamin K2. Vitamin K activates proteins involved in building bone and in keeping calcium out of blood vessels, including osteocalcin and matrix Gla protein. In a three-year trial of 244 healthy postmenopausal women, 180 micrograms a day of MK-7, a long-acting form of vitamin K2, slowed the loss of bone density at the lower spine and femoral neck, though not at the total hip (Knapen et al., 2013). The wider evidence is mixed. A 2019 review of 36 trials found no evidence that vitamin K changes bone density or spine fractures in postmenopausal or osteoporotic women. It may lower other fractures, but the evidence is too thin to confirm it (Mott et al., 2019). In the Rotterdam Study of 4,807 men and women, those who ate the most vitamin K2 had less severe calcification of the aorta and a lower rate of death from heart disease (Geleijnse et al., 2004). That study recorded what people ate; it tested no supplements.
Vitamin D. The body needs vitamin D to absorb calcium. Ask your doctor whether your diet, health conditions, medications or bone health make a vitamin D supplement or a blood test right for you.
This is the argument I made years ago in Minerals: The Forgotten Nutrient: the body's minerals work as a network, and correcting one mineral while ignoring the others that work with it leads to predictable problems.
Calcium supplements show why this matters. A 2010 analysis of randomized trials found that calcium supplements taken without vitamin D were linked to a higher risk of heart attack (Bolland et al., 2010). A 2011 analysis that added the Women's Health Initiative data found a modest rise in cardiovascular events, mainly heart attacks, with or without vitamin D (Bolland et al., 2011). A 2016 review reached a different conclusion: calcium intake within the upper limit of 2,000 to 2,500 mg a day was not linked to heart disease in generally healthy adults (Chung et al., 2016). Calcium from food has not shown the same warning sign. The observational studies Bolland's team reviewed found no higher heart risk with more dietary calcium (Bolland et al., 2010).
Why might supplements differ from food? Bolland's group proposed that the cause is the sudden rise in blood calcium after a supplement dose (Bolland et al., 2011). Other researchers point to vitamin K2, because the protein it activates, matrix Gla protein, helps keep calcium out of artery walls (Geleijnse et al., 2004). No study cited here tests whether vitamin K2 offsets any heart risk from calcium supplements.
The practical point: keep calcium, get most of it from food, and pay attention to magnesium and vitamin D. Vitamin K2 (MK-7 is the form studied for bone) has one positive trial for bone density, and the wider evidence is mixed.
A safety note. If you take warfarin, do not start vitamin K2 without talking to your doctor. In a study of healthy volunteers taking a similar drug, MK-7 at doses as low as 10 micrograms a day changed how well the drug thinned the blood in some people, and the authors concluded that MK-7 supplements should be avoided by people on these drugs (Theuwissen et al., 2013). If you take any blood thinner, check with your doctor or pharmacist before adding a supplement.
The mechanical signal
The second gap in the standard advice is load. Harold Frost's "mechanostat" describes how bone adjusts its strength to the loads placed on it. In his words, "voluntary mechanical usage determines most of the postnatal strength of healthy bones" (Frost, 2003). Bone that carries regular load keeps its strength. Bone that carries little load is allowed to weaken.
Walking is the exercise most often recommended to older women, and it gives bone a weak signal. A review of eight walking trials in previously sedentary postmenopausal women found no significant effect on spine bone density. At the femoral neck, the five trials with data showed a small gain that only just reached statistical significance and varied from trial to trial. The authors concluded that walking helps the femoral neck, and that "other forms of exercise that provide greater targeted skeletal loading may be required" (Martyn-St James & Carroll, 2008). Walking is good for general health. On its own it is not enough to protect bone.
The strongest evidence on what does build bone in women with low bone mass comes from the LIFTMOR trial (Watson et al., 2018). Researchers randomly assigned 101 postmenopausal women with low bone mass, average age 65, either to supervised high-intensity resistance and impact training (30 minutes, twice a week) or to a low-intensity home program. After eight months, the high-intensity group had gained 2.9% in spine bone density while the home group lost 1.2%. At the femoral neck, the high-intensity group gained 0.3% and the home group lost 1.9%. The high-intensity group also did better on all the physical function tests it measured and on height. One adverse event was reported in the high-intensity group: a minor lower back spasm.
LIFTMOR has limits. It measured bone density and physical function and was not designed to show whether training prevents fractures, which would need larger and longer trials. Training was closely supervised, and the women were screened for conditions and medications that affect bone and movement. The results do not support unsupervised training.
Within those limits, the trial fits what its authors describe: bone responds best to high loads applied quickly. A position statement from Exercise and Sports Science Australia also recommends impact activities and high-intensity progressive resistance training, with each program fitted to the person's bone health, other conditions and risk of falls and fracture (Beck et al., 2017).
The safety boundary
This evidence applies to supervised training. Women with osteoporosis should not start heavy lifting on their own. Bending the spine forward under load is the main concern. In a small 1984 study of 59 women with spinal osteoporosis, 89% of the nine women given forward-bending (flexion) exercises had new spine fractures, compared with 16% of the 25 given back-extension exercises (Sinaki & Mikkelsen, 1984). The women were not randomly assigned, so the study shows an association and cannot prove cause. A later report described three people with low bone mass who developed pain or spine fractures after yoga poses that bend the spine forward (Sinaki, 2013). The Australian position statement says loaded spine flexion is not recommended (Beck et al., 2017).
The international Too Fit To Fracture panel strongly recommends exercise that includes resistance and balance training for people with osteoporosis or spine fractures (Giangregorio et al., 2014). It advises teaching spine-sparing ways to move, such as hinging at the hips, rather than blanket rules like "never lift more than 10 pounds." For people who already have spine fractures, especially with pain, several fractures or a pronounced forward curve of the upper back, it recommends seeing a physical therapist (Giangregorio et al., 2015).
The default cultural message to older women is to become more cautious. The evidence-informed message is to become more skillfully challenged.
What this means in practice
Nutrition: enough protein; calcium mainly from food; vitamin D, with your doctor deciding whether you need a supplement or a blood test; magnesium, with your doctor deciding whether you need a supplement if your diet falls short or you are at risk of deficiency; and vitamin K2 only as an option to discuss, never with warfarin or a similar drug unless your doctor approves.
Exercise: progressive resistance training heavy enough to challenge you, balance and posture work, and, where appropriate and supervised, impact exercise. Walking supports general health and should not be your only exercise for bone.
Screening: the U.S. Preventive Services Task Force recommends osteoporosis screening for women 65 and older and for younger postmenopausal women at increased risk (USPSTF, 2025). Ask whether you need a bone density test.
Medicine: hormone therapy and bone medications have their own evidence and their own risks. If your fracture risk is high, ask your clinician about them. The decision is yours to make with your clinician.
Calcium and vitamin D still matter. Taken as supplements on their own, they have not been shown to prevent fractures in postmenopausal women living at home. The U.S. Preventive Services Task Force recommends against daily supplements of 400 IU or less of vitamin D and 1,000 mg or less of calcium to prevent fractures in postmenopausal women living in the community, and found too little evidence to judge higher doses (USPSTF, 2018). A December 2024 draft update, not yet final, recommends against vitamin D with or without calcium for preventing a first fracture in postmenopausal women (USPSTF, 2024 draft). These recommendations cover generally healthy adults living at home. They do not apply to people with osteoporosis, vitamin D deficiency, a past osteoporotic fracture or a higher risk of falls. Bone health needs a whole plan: nutrition, loading, fall prevention, a fracture-risk assessment and medication when it is called for.
Joy Stephenson-Laws, JD, is the founding and managing partner of Stephenson, Acquisto & Colman, a healthcare litigation firm, and the founder and president of Proactive Health Labs, a national nonprofit focused on evidence-based health literacy. A healthcare attorney for more than forty years and a certified holistic wellness coach, she writes about how people can partner with their doctors without surrendering their own judgment.
Her books include Your Labs Are Fine. You're Not., Advice on Trial: The Beliefs You Inherited but Never Examined, From Chains to Wings: A Poetry Revolution for Healing, Secrets That Sparkle (and Secrets That Sting), and Minerals - The Forgotten Nutrient: Your Secret Weapon for Getting and Staying Healthy.
(This article is for general education and is not medical advice. It is meant to help you ask better questions, not to replace evaluation by a qualified clinician).
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