Why midlife is the perfect time to get serious about vitamin D

Midlife is often when we start thinking differently about health. It’s less about quick wins and more about staying strong, steady, and active for the long haul. One nutrient that quietly underpins all of that is vitamin D.

What does vitamin D do and how does it help my bones?

Often called the ‘sunshine vitamin’, vitamin D helps your body absorb and use calcium, the essential mineral that keeps bones strong. The reassuring part is that supporting your bones doesn’t need extreme routines or overthinking. A few smart habits can make a real difference.

Bone density peaks at age 30. From then on, changes in bone density and muscle strength happen gradually and often unnoticed, until they start to matter. Vitamin D supports both bones and muscles, helping you stay mobile, balanced and confident in your movement, whether you’re walking the dog, running, weight training or simply chasing everyday life.

How much vitamin D do you need?

Most adults need 10 micrograms (400 IU) of vitamin D a day. You might see either measurement on supplement labels but they mean the same thing (1 microgram equals 40 IU).

If you know that you’re at higher risk of osteoporosis or taking bone-strengthening medication, a healthcare professional may recommend a higher daily dose to make sure your bones stay well supported.

More isn’t better though. Very high doses (more than 100 micrograms or 4000 IU a day) taken over a long period can be harmful, so it’s important to check labels, especially if you take multivitamins or other supplements that may already contain vitamin D.

Which foods contain vitamin D?

Vitamin D shows up naturally in only a handful of foods. Oily fish such as salmon, mackerel and herring are the richest sources, alongside eggs and red meat. Some cereals, yoghurts and breads are also fortified with vitamin D.

These foods contribute, but even with a balanced diet it’s difficult to get enough vitamin D from food alone. That’s why sunlight in summer and supplements in winter usually remain the most reliable combination.

Men and women alike can lose bone strength over time, particularly if they’re less active, spend little time outdoors or have low vitamin D levels. Midlife is the ideal moment to protect what you’ve built so far, giving your body the support it needs to help reduce the risk of problems later.

Does sunscreen block vitamin D?

Sunlight is your body’s most natural source of vitamin D. In the UK, your skin can make vitamin D from sunlight between early April and the end of September.

During these months, exposing your face and arms to direct sunlight for around 10 minutes once or twice a day is usually enough for bone health. You don’t need to sunbathe, and more isn’t better. Short, regular exposure works best and helps avoid skin damage.

Current research also suggests that sunscreen does not block vitamin D production, so protecting yourself against sunburn is still important.

For those that work at home, try to take regular breaks by walking outdoors to catch a bit of sunshine while it’s here to enjoy.

Even on cloudy days your skin can still produce vitamin D, although it may take a little longer. Just be mindful to avoid the strongest midday sun (between 11am and 3pm) and use sunscreen if you’re outdoors for longer periods.

Should you take a vitamin D supplement in winter?

Once autumn arrives, things change. From the end of September to the beginning of April, sunlight in the UK simply isn’t strong enough for your skin to make vitamin D no matter how active you are.

“Looking after your bones isn’t about becoming cautious; it’s about staying capable,” says ROS specialist osteoporosis nurse, Kirsty Carne. “Vitamin D works quietly behind the scenes, supporting strength, stability and movement so you can keep doing the things you enjoy, now and in the years ahead.

“A little sunshine when it’s available, a daily supplement when it’s not, and a balanced diet alongside both can help keep your bones strong, supported and ready for whatever midlife and beyond has in store.

“We recommend that most adults consider taking a daily vitamin D supplement during the winter months. Many people in midlife also choose to take one all year round, especially if they spend little time outdoors, tend to cover their skin, use sunscreen most of the time, or have darker skin. Think of it as a seasonal insurance policy for your bones.”

Can you take too much vitamin D?

Yes, taking too much vitamin D can cause hypercalcemia, where there is too much calcium in the blood. This can make bones weaker and cause damage to your kidneys and heart.

Symptoms of vitamin D overdose can include feeling sick (nausea), vomiting, poor appetite, constipation, weakness, and confusion. People may also feel very thirsty and need to urinate more often. In more serious cases, high calcium levels can lead to kidney stones, kidney damage, or abnormal heart rhythms.

It’s important to understand that the body naturally controls how much vitamin D is made from sunlight, so sun exposure cannot cause an overdose. Similarly, foods like oily fish, red meat, fortified breakfast cereals or margarine and egg yolks don’t usually contain enough vitamin D to cause harm.

If you’re unsure about your vitamin D levels or the best dose of vitamin D for you, it’s best to speak to a healthcare professional.

What’s the difference between vitamin D2 and vitamin D3?

Vitamin D comes in two forms - vitamin D2 and vitamin D3. D2 (which is ergocalciferol) is mainly found in plant-based sources, and D3 (cholecalciferol) is mainly animal based - for example, in the oily fish mentioned above. D3 is better at raising vitamin D levels in the blood but D2 may be a useful option for vegetarians or vegans.

Vitamin D3 is the form your skin naturally makes in sunlight and the form most recommended in supplements.

Know your risk factors for osteoporosis

Eating a healthy, balanced diet can help you get all the nutrients you need to keep your bones strong. This includes calcium, vitamin D and other vitamins and minerals.

Not getting enough key nutrients is one of the risk factors for osteoporosis you can change.

Take our free, 3-minute risk checker today to understand your risk of broken bones.