Osteoporosis creeps up quietly. There’s no pain, no warning signs, no symptoms at all until a bone breaks. By that point, the damage is already done. This is why prevention matters so much more than treatment when it comes to bone health.

The good news? What you eat genuinely affects your bones. I’m not talking about miracle supplements or expensive powders. I’m talking about nutrients your body actually needs to build and maintain strong bones throughout your life.

According to the International Osteoporosis Foundation, roughly 200 million people worldwide have osteoporosis 1. About half of women and a quarter of men over 50 will experience a fragility fracture at some point. These aren’t small numbers, and they’re growing as populations age.

What is osteoporosis, exactly?

Your bones aren’t static structures. They’re living tissue that constantly breaks down and rebuilds itself. Osteoporosis happens when your body removes old bone faster than it can create new bone. The result: bones become porous, weak, and prone to fractures.

There are two main types:

Primary osteoporosis is the most common form. It develops naturally with age, particularly in women after menopause when oestrogen levels drop sharply. Oestrogen helps protect bone density, so losing it accelerates bone loss.

Secondary osteoporosis is caused by other factors: certain medications (like long-term corticosteroids), medical conditions (such as hyperthyroidism or coeliac disease), or lifestyle factors.

The spine and hips take the worst of it. Hip fractures in particular are devastating. The NHS reports that about 50% of people who break a hip never regain their previous level of mobility 2. Some require permanent care.

This is why building strong bones when you’re young and maintaining them as you age isn’t optional. It’s genuinely important for your long-term quality of life.

1. Calcium and Vitamin D (these two work together)

You’ve heard this one before, and for good reason. Calcium is quite literally what your bones are made of. About 99% of the calcium in your body sits in your bones and teeth. The remaining 1% circulates in your blood to support nerve function, muscle contraction, and blood clotting.

Here’s the catch: if you don’t get enough calcium from food, your body will take it from your bones to maintain that crucial 1% in your blood. Your bones essentially become a calcium savings account that your body raids when supplies run low.

For more detailed information about calcium supplementation, see our article on calcium tablets and their effects.

But calcium alone isn’t enough. This is where vitamin D enters the picture.

Vitamin D acts like a gatekeeper that controls how much calcium your gut actually absorbs. Without adequate vitamin D, you could eat all the calcium-rich foods in the world and still not absorb enough. Studies show that vitamin D deficiency (below 25-30 nmol/L) is strongly associated with muscle weakness, reduced mobility, and increased fall risk 3.

Falls matter enormously for osteoporosis. A bone that’s become porous might survive daily activities just fine but break from a relatively minor fall. Preventing falls is half the battle.

How much do you need?

The NHS recommends 700mg of calcium daily for adults, with most people able to get this from diet alone. For vitamin D, the recommendation is 10 micrograms (400 IU) daily, particularly during autumn and winter when sunlight exposure drops.

Good food sources of calcium:

Dairy products (milk, cheese, yoghurt)
Fortified plant milks
Sardines and pilchards with bones
Green leafy vegetables like kale and broccoli
Tofu made with calcium sulphate
Fortified cereals

Good sources of vitamin D:

Oily fish (salmon, mackerel, sardines)
Egg yolks
Fortified foods
Mushrooms exposed to UV light
Sunlight (though this varies by latitude and season)

For a deeper dive into vitamin D, including dosing and potential side effects, check out our comprehensive guide on vitamin D benefits and contraindications.

My take: If you’re eating dairy regularly and getting some sunlight, you’re probably fine on calcium. Vitamin D is trickier, especially if you live in the UK where sunlight is limited for much of the year. A daily supplement during winter months is worth considering.

2. Vitamin K

Vitamin K doesn’t get nearly as much attention as calcium and vitamin D, but the research on its role in bone health has grown considerably in recent years.

Vitamin K is a fat-soluble vitamin that comes in two main forms: K1 (found in green leafy vegetables) and K2 (found in fermented foods and animal products). Both play roles in bone metabolism, though K2 appears to be particularly important for bones.

Here’s what vitamin K actually does: it activates proteins that bind calcium to your bones, most notably osteocalcin. Without enough vitamin K, osteocalcin remains inactive, and calcium doesn’t get deposited into bone as efficiently 4.

A meta-analysis of nine studies involving 6,759 participants found that vitamin K2 supplementation helped maintain and improve spinal bone density in postmenopausal women with osteoporosis. The same analysis noted reductions in undercarboxylated osteocalcin (a marker of vitamin K deficiency) and increases in active osteocalcin, suggesting genuine effects on bone metabolism 5.

Good food sources of vitamin K2:

Natto (fermented soybeans) - by far the richest source
Cheese, particularly aged varieties
Egg yolks
Chicken
Butter from grass-fed cows
Liver

Vitamin K1 sources:

Kale
Spinach
Broccoli
Brussels sprouts
Cabbage

For detailed information about vitamin K, including safety considerations and drug interactions, see our article on vitamin K effects and contraindications.

Worth noting: If you take blood thinners like warfarin, you need to be careful with vitamin K. It can interfere with how these medications work. Don’t dramatically increase or decrease your vitamin K intake without talking to your doctor.

My assessment: The evidence for vitamin K2 is promising but not yet definitive. It’s probably not going to single-handedly prevent osteoporosis, but ensuring adequate intake through diet seems sensible. Natto is an acquired taste, to put it mildly, but aged cheese and egg yolks are perfectly pleasant ways to get more K2.

3. Vitamin C

Vitamin C is famous for immune support, but its role in bone health often gets overlooked. It turns out that vitamin C is essential for collagen synthesis, and collagen provides the structural framework that calcium and other minerals attach to. Think of it as the scaffolding that holds everything together.

Animal studies have shown that vitamin C’s antioxidant and anti-inflammatory properties benefit bone health through several mechanisms: inhibiting cells that break down bone (osteoclasts), promoting bone-building cells (osteoblasts), and enhancing calcium absorption 6.

Human research backs this up. A cohort study of over 3,000 people aged 50 and older found that higher vitamin C intake was associated with 30-50% lower risk of osteoporosis, particularly in those who didn’t exercise regularly 7. Another study in the same population found that those with the highest vitamin C intake from dietary sources had 44% lower risk of hip fracture and 26% lower risk of non-vertebral fractures compared to those with the lowest intake 8.

Good food sources of vitamin C:

Citrus fruits (oranges, lemons, grapefruit)
Berries (strawberries, blackcurrants)
Kiwi fruit
Bell peppers
Broccoli
Brussels sprouts
Potatoes (surprisingly, they contribute significantly to UK vitamin C intake)

For more on vitamin C, including dosing considerations and what happens with excess intake, see our detailed guide on vitamin C benefits and contraindications.

The reality: Most people eating a reasonable diet with fruits and vegetables get plenty of vitamin C. Deficiency is uncommon in developed countries. That said, the research suggests that being on the higher end of intake may offer bone benefits, especially if you’re not particularly active.

4. Collagen-supporting nutrients

While not a single nutrient, I want to mention the broader category of nutrients that support collagen production, because collagen makes up about 90% of the organic matrix of bone.

Beyond vitamin C (which I covered above), these include:

Protein: You need adequate protein to build collagen. Older adults often don’t eat enough protein, which can contribute to muscle and bone loss. The research suggests that protein intake higher than the basic recommended daily amount may benefit bone health in older adults, particularly when combined with calcium and vitamin D 9.

Zinc: Involved in bone tissue renewal and mineralisation. Found in meat, shellfish, legumes, and seeds.

Copper: Necessary for collagen cross-linking, which gives bones their strength and flexibility. Found in shellfish, nuts, seeds, and organ meats.

Manganese: Required for bone formation and cartilage health. Found in whole grains, nuts, and leafy vegetables.

For those interested in collagen specifically, we have a detailed article on collagen benefits and contraindications.

In practice: You don’t need to obsess over each of these individually. A varied diet that includes quality protein sources, vegetables, and whole grains will cover most of them. The people most at risk of deficiencies are those with very restricted diets.

Beyond nutrition: other factors that matter

Diet is only part of the picture. Several other factors influence your bone health:

Exercise: Weight-bearing exercise stimulates bone growth. This includes walking, jogging, dancing, climbing stairs, and resistance training. Your bones respond to mechanical stress by getting stronger. Swimming and cycling, while excellent for cardiovascular health, don’t load your bones the same way.

Smoking: Smokers have significantly lower bone density and higher fracture risk. Quitting helps.

Alcohol: Heavy drinking interferes with calcium absorption and bone formation. Moderate consumption (within guidelines) appears to be fine.

Medications: Some medications, particularly long-term corticosteroids, accelerate bone loss. If you’re on such medications, your doctor should be monitoring your bone health.

Genetics: Some of this is out of your control. If osteoporosis runs in your family, you have higher risk.

Timing matters: The bone mass you build in your teens and twenties sets you up for the rest of your life. Peak bone mass is typically reached by around age 30. After that, the goal shifts from building to maintaining. If you can build stronger bones in youth, you can reduce osteoporosis risk by up to 60%.

Summing up

Preventing osteoporosis isn’t about taking a single magic supplement. It’s about ensuring your body has all the raw materials it needs for bone maintenance, combined with the mechanical stimulation that tells your bones to stay strong.

The four nutrient categories that matter most:

Calcium and Vitamin D - the foundation of bone health, working together for proper absorption
Vitamin K - activates proteins that bind calcium to bones
Vitamin C - essential for collagen, the structural framework of bone
Collagen-supporting nutrients - protein, zinc, copper, and manganese that maintain bone structure

Most people can get adequate amounts of these from a balanced diet. Supplements may be helpful in specific situations (vitamin D in winter, calcium if you don’t eat dairy), but they’re not a substitute for eating properly.

If you’re concerned about your bone health, particularly if you have risk factors like family history, early menopause, or long-term steroid use, talk to your GP. A DEXA scan can measure your bone density and help determine whether you need more aggressive intervention.

References:

Sözen T, et al. An overview and management of osteoporosis. Eur J Rheumatol. 2017 PubMed
NHS. Osteoporosis - Overview. NHS
Halfon M, et al. Vitamin D: A Review on Its Effects on Muscle Strength, the Risk of Fall, and Frailty. Biomed Res Int. 2015 PubMed
Akbari S, Rasouli-Ghahroudi AA. Vitamin K and Bone Metabolism: A Review of the Latest Evidence in Preclinical Studies. Biomed Res Int. 2018 PubMed
Huang ZB, et al. Does vitamin K2 play a role in the prevention and treatment of osteoporosis for postmenopausal women: a meta-analysis of randomized controlled trials. Osteoporos Int. 2015 PubMed
Aghajanian P, et al. The Roles and Mechanisms of Actions of Vitamin C in Bone: New Developments. J Bone Miner Res. 2015 PubMed
Park HM, et al. Relationship between vitamin C intake and osteoporosis in Korean elderly. Nutrients. 2018 PubMed
Sahni S, et al. Vitamin C supplementation and bone density: Results from the Framingham Osteoporosis Study. J Nutr. 2009 PubMed
Rizzoli R, et al. Benefits and safety of dietary protein for bone health. Osteoporos Int. 2018 PubMed