Bones: calcium, vitamin D and the foods that carry them

Bone does not complain until something breaks. But it is living tissue, constantly taken down and rebuilt, and after 50 the rebuilding needs two things in reliable supply: calcium to build with, and vitamin D so your body can use it.

This is general information, not dietary advice. If you have osteoporosis, take bone medicine, have kidney problems, or are considering a supplement, check with your GP (family doctor) first. This article gives no supplement doses — the official pages linked below do that job, and your GP can tell you what applies to you.

What the two nutrients do

The NHS (the UK health service) says calcium helps in “building bones and keep teeth healthy, regulating muscle contractions, including your heartbeat, making sure blood clots normally.” Vitamin D “helps regulate the amount of calcium and phosphate in the body.” They work as a pair.

The US National Institutes of Health lists what happens when calcium runs short: “Osteoporosis, which causes weak, fragile bones and increases the risk of falls and fractures.” The US guidance for older adults adds that calcium and vitamin D are both under-consumed by the general population, and that “low intakes are a public health concern.”

How much calcium?

• UK: the NHS says adults “need 700mg of calcium a day.” The Royal Osteoporosis Society uses the same figure, and adds that “if you’re at risk of osteoporosis or taking an osteoporosis medicine, your doctor may advise you to increase your intake to around 1,000mg of calcium a day.”
• US: the NIH Office of Dietary Supplements gives 1,000mg a day for men aged 51–70, 1,200mg for women aged 51–70, and 1,200mg for everyone from 71.

Whichever figure you work to, the US foundation’s advice is the useful bit: “Food is the best source of calcium”, and “there is no added benefit to taking more calcium than you need.” The NHS warns that “more than 1,500mg a day” from supplements “could lead to stomach pain and diarrhoea.”

Where calcium comes from

The Royal Osteoporosis Society’s food chooser gives calcium per portion. A 700mg day is roughly three or four of the 200mg lines below plus the odd smaller one.

Dairy is the easy route — milk, yoghurt and cheese is most of the UK figure. The non-dairy options are real: tinned sardines, calcium-set tofu and kale match milk portion for portion, while an orange is a rounding error. Bread counts too — the NHS lists “bread and anything made with fortified flour”. One caution from both the NHS and the ROS: “green leafy vegetables – such as curly kale, okra but not spinach.” Spinach’s calcium is not in a form your body uses well.

In the US, the NIH notes that fortified juices, soya and almond drinks, some tofu and breakfast cereals fill the gap for people who avoid dairy. Check the label.

Vitamin D: sun first, then food, then the official guidance

Most vitamin D does not come from food. The NHS says that “from about late March or early April to the end of September, most people should be able to make all the vitamin D they need from sunlight.” A walk with your sleeves rolled up does it.

Food contributes less. The NHS lists oily fish “such as salmon, sardines, trout, herring or mackerel”, red meat, liver, egg yolks and fortified foods. In the US, “almost all of the U.S. milk supply is fortified” with vitamin D; in the UK, check the label on spreads, cereals and plant drinks.

The catch is the darker half of the year, and age: the NIH notes that “clouds, smog, old age, and having dark-colored skin reduce the amount of vitamin D your skin makes.” Both governments publish daily amounts for adults, and the NHS has separate guidance on what to consider taking in autumn and winter, and year-round if you are rarely outdoors or have darker skin. We are not repeating the figures here — read the NHS page or the NIH fact sheet linked below, and ask your GP or pharmacist whether it applies to you. More is not better: the NHS sets an upper daily limit and says exceeding it “could be harmful.”

Bringing it together

Calcium from food at every meal, daylight when the season allows, and the autumn-and-winter guidance discussed with your GP. Bones also respond to load — the strength work in our Move guides is the other half of the story.

If you want it built into a week of meals rather than bolted on, our Eat Strong four-week kitchen planner gives bones a week of its own alongside protein and fibre. For the wider picture start with Eating well after 50: the complete, no-fad guide; for the muscle side see Protein after 50.

This week

• Add one 200mg food from the table to a meal that currently has none.
• Get outside in daylight with some skin uncovered, every day the weather allows.
• Read the NHS or NIH vitamin D page and write down one question for your GP.