How bone density changes as you age

Learn how bone density changes with age and how calcium, vitamin D, magnesium and weight-bearing exercise support strong bones for healthy ageing.

Bone is living tissue. It renews itself throughout life, with old bone broken down and new bone built in its place through a process called remodelling. Bone density builds to a peak in early adulthood, holds relatively steady for a period, then gradually shifts as the years go on. Understanding that cycle is the starting point for looking after your bones at any age.

This article explains why bone health becomes more of a priority as you get older, how bone density changes across life, and the roles that nutrition, movement and muscle strength play in maintaining strong bones. It covers calcium, vitamin D and magnesium, the value of weight bearing activity, and how to build a bone health routine that fits everyday life.

Why strong bones matter for healthy ageing

Your skeleton does more than hold you upright. It protects organs, anchors muscles, stores minerals such as calcium, and gives your body the framework for movement. Bones that stay dense and strong support mobility, balance and independence as you age.

Bone density tends to decline gradually in later life, and lower bone mineral density is linked with a higher risk of falls and fractures. According to the Australian Institute of Health and Welfare's 2024 analysis, low bone mineral density accounted for 29% of the fall related disease burden in Australia in 2018. Looking after bone health across the decades is a way of protecting the freedom to keep doing the things that matter to you.

What happens to bone density as we age

Bone mass grows rapidly through childhood and adolescence. According to the NHMRC Nutrient Reference Values, bone mass increases around sevenfold between birth and puberty and a further threefold during adolescence, with peak bone mass reached at roughly the same time as maximum height.

After that peak, bone mass stays relatively stable until about age 50 in men and until menopause in women. The same NHMRC reference notes that for around 5 to 10 years during and after menopause, women lose bone more rapidly than men, at about 2 to 3% per year. From then on, the age related rate of loss in both sexes settles at around 0.5 to 1% per year. This pattern is a normal part of ageing, and it helps explain why bone health draws more attention from midlife onwards.

Key life stages where bone health becomes more important

Bone needs change across a lifetime, and a few stages carry more weight than others. Childhood and adolescence are when the body lays down most of its peak bone mass, and the higher that peak reaches in early adulthood, the greater the reserve to draw on later. Through the 30s and 40s the focus shifts to holding onto that bone, which nutrition and regular activity help to do.

For women, the years around menopause bring a faster phase of bone loss tied to falling oestrogen. Healthy Bones Australia notes that oestrogen plays a role in maintaining bone strength, so the hormonal changes of this stage can affect bone density. From there, a steady and gradual decline continues for both men and women.

Nutrient needs move in step with these stages. The Australian Bureau of Statistics reported in 2023 that calcium requirements rise for older adults experiencing bone mass changes, from 50 years of age for males and after menopause for females.

Calcium, vitamin D and magnesium: how key nutrients support bone health

Several nutrients contribute to bone health, and three are worth understanding in detail.

Calcium

Calcium is the main mineral stored in bone and gives the skeleton its structure and hardness. The recommended daily intake in Australia, as set by the NHMRC Nutrient Reference Values, is 1000mg a day for most adults, rising to 1300mg a day for women over 50 and men over 70.

Many Australians fall short of these targets from diet alone. The Australian Bureau of Statistics found in 2023 that more than 60% of Australians did not meet their calcium needs from food, a figure largely unchanged since 2011 to 2012, with the shortfall more pronounced among women. Calcium rich foods include dairy such as milk, yoghurt and cheese, along with tinned sardines and salmon with bones, tofu set with calcium, almonds, and leafy green vegetables.

Vitamin D

Vitamin D works closely with calcium. According to Healthdirect, vitamin D helps the body absorb calcium from food and helps control calcium levels in the blood, both of which support bone development and strength. For most Australians the main source is sensible sun exposure, since very little vitamin D comes from food. Dietary sources that do contribute include oily fish, eggs and some fortified milks and margarines. You can read more in the Blackmores complete guide to vitamin D.

Magnesium

Magnesium is often overlooked in bone conversations, yet the skeleton is its main storage site. The NHMRC Nutrient Reference Values describe magnesium as playing a role in the metabolism of calcium, with the recommended daily intake set at 420mg for men aged 31 and over and 320mg for women in the same age group. The Australian Bureau of Statistics reported in 2023 that 31% of Australians did not meet their magnesium requirements from food. Good dietary sources include green leafy vegetables, nuts, seeds, legumes and whole grains.

The role of weight bearing movement in maintaining bone strength

Bone responds to load. When muscles pull on bone and impact travels through the skeleton, that mechanical strain signals the body to maintain bone tissue. Healthy Bones Australia notes that bones benefit when a certain amount of impact or strain is placed on them, which is why some forms of exercise matter more than others for bone.

Weight bearing and resistance activities are the standouts. A 2025 systematic review and meta-analysis in the Journal of Orthopaedic Surgery and Research, found that resistance training was associated with higher bone mineral density at the lumbar spine and femoral neck. Weight bearing options include walking, jogging, stair climbing, dancing and tennis, while resistance work covers lifting weights, resistance bands and body weight exercises. Activities like swimming and cycling are excellent for general fitness, though they place less loading strain on bone.

How muscle strength and balance help protect bones

Strong bones and strong muscles work as a team. Muscle strength supports posture and movement, while good balance reduces the likelihood of a fall in the first place. Since lower bone mineral density is linked with fall related fractures, keeping muscles capable and balance steady is part of the wider picture of bone protection.

Protein provides the building blocks for muscle, and Healthy Bones Australia notes that adequate protein supports bone mass and structure alongside muscle. Vitamin D contributes here too, playing a role in muscle function as well as calcium absorption. Balance focused activities such as tai chi, yoga and simple standing balance drills can be a practical addition to a movement routine, particularly in later life.

Everyday habits that may affect bone health

Several lifestyle factors influence how well bone density is maintained over time. The AIHW notes that risk factors associated with bone loss include smoking, excess alcohol, physical inactivity and low body weight.

Habits that support bone health include:

• Eating a varied diet with regular calcium rich foods across the day
• Getting sensible sun exposure to support vitamin D, balanced against sun safety
• Including weight bearing and resistance movement most weeks
• Reaching adequate protein at meals to support muscle and bone
• Keeping alcohol within recommended limits and not smoking
• Maintaining a healthy body weight

Because bone loss usually happens quietly, these everyday choices tend to matter more than any single intervention. The AIHW points out that bone loss often has no obvious signs and may go unnoticed until later, which is why consistent habits over the years count.

Supplementation considerations for bone health

Food and sunlight are the foundation for bone nutrition. Where dietary intake falls short, supplements may help fill the gap, and can only be of assistance when dietary intake is inadequate.

For those looking to bring calcium and magnesium together, Blackmores Total Calcium + Magnesium + D3 is formulated with three forms of calcium (calcium citrate, calcium phosphate and calcium amino acid chelate), alongside magnesium, vitamin D3, and smaller amounts of zinc, manganese and vitamin K1. Calcium and vitamin D contribute to the maintenance of normal bones, and magnesium is involved in bone health, so the combination reflects how these nutrients work together in the body.

Magnesium can also be taken on its own as part of a daily routine. The Blackmores magnesium range includes several formulations developed with different priorities in mind, from everyday intake to muscle and sleep support. Choosing where a supplement fits is worth discussing with a pharmacist or healthcare professional, particularly if you already take other products.

When to speak to a healthcare professional about bone density

Bone density can be measured with a specialised scan known as a DXA scan, which the AIHW describes as the standard method for assessing bone mineral density, with results expressed as a T-score. Speaking with your GP is a sensible step if you have a family history of low bone density, have had a fracture from a minor bump or fall, are going through or past menopause, or have other risk factors such as long term corticosteroid use.

A healthcare professional can assess your individual situation, arrange a bone density test if appropriate, and tailor advice on nutrition, movement and any further steps. The AIHW notes that bone loss is largely preventable, and early attention to risk factors is a practical part of healthy ageing.

Building a long term bone health routine

A bone friendly routine does not need to be complicated:

• Include a calcium rich food at most meals, such as yoghurt at breakfast or tinned fish at lunch.
• Spend a little time outdoors for sensible sun exposure, within sun safe guidelines.
• Add two or more sessions of weight bearing or resistance activity each week.
• Work in some balance practice, especially as you get older.
• Keep protein steady across the day to support muscle.
• Review your diet and any supplements with a professional if you are unsure of the gaps.

Consistency over months and years shapes bone health far more than any single day. Small, repeated choices are what build the routine.

Frequently asked questions

When does bone density start to decline?

Bone mass tends to stay stable until around age 50 in men and until menopause in women. Women then experience a faster phase of loss for several years, before both sexes settle into a gradual decline of around 0.5 to 1% per year.

What nutrients support bone health?

Calcium provides the main structural mineral in bone, vitamin D helps the body absorb calcium, and magnesium is involved in bone health and calcium metabolism. Protein and vitamin K also contribute. A varied diet is the best way to cover them.

Calcium vs vitamin D vs magnesium: what is the difference for bones?

Calcium is the mineral that gives bone its hardness. Vitamin D helps you absorb that calcium from food. Magnesium supports the way the body handles calcium and is stored largely in bone. The three work together rather than in isolation.

Does exercise support bone density?

Weight bearing and resistance activity place strain on bone that signals it to maintain tissue. Research in postmenopausal women has linked resistance training with higher bone mineral density at the spine and hip, so movement is a meaningful part of bone care.

Why is bone health important for women after 45?

As women approach and pass menopause, falling oestrogen is linked with a faster phase of bone loss. This makes the years around and after menopause a useful time to focus on nutrition, movement and, where needed, a bone density check.

How can I keep my bones strong as I age?

Aim for adequate calcium and vitamin D, include weight bearing and resistance movement, keep muscles and balance in good shape, and limit smoking and excess alcohol. Speak with your GP about a bone density test if you have risk factors.

Key takeaways

Bone is living tissue that reaches peak density in early adulthood and gradually changes with age, with a faster phase of loss for women around menopause. Calcium, vitamin D and magnesium each contribute to bone health, and many Australians fall short of recommended calcium and magnesium intakes from diet alone.

Weight bearing and resistance movement, adequate protein, and steady everyday habits all support bone strength and the muscle and balance that help prevent falls. Where diet leaves gaps, supplements may be of assistance when dietary intake is inadequate. Because bone loss is usually silent, consistent care over the years is the most practical approach, and a healthcare professional can guide bone density testing where risk factors are present.

Always read the label and follow the directions for use.

Disclaimer: This article provides general information only and is not intended to diagnose, treat, cure, or prevent any disease. The information presented is not a substitute for professional medical advice. If you have concerns about your health, please consult your GP or healthcare provider for a personalised assessment and recommendations. Supplements should not replace a balanced diet.