Your vitamin D levels can drop in summer — even on sunny days — because sunscreen, window glass, clothing, cloud cover, and the natural thinning of skin that comes with age all reduce how much vitamin D your body can make from sunlight. Adults over 60 produce roughly four times less vitamin D from the same sun exposure than a 20-year-old does, making summer sun far less reliable than most people assume. The good news is that understanding why this happens makes it straightforward to fix.

Why does sunscreen block vitamin D production?

Sunscreen works by absorbing or reflecting ultraviolet B (UVB) rays — the exact wavelength your skin needs to trigger vitamin D synthesis. An SPF 30 sunscreen, applied correctly, blocks around 97% of UVB radiation. That is brilliant news for skin cancer prevention, which matters enormously as we age, but it does mean your skin is producing almost no vitamin D while you wear it.

The practical reality is that most of us don’t apply sunscreen perfectly — we miss patches, use too little, or forget to reapply — so some synthesis still happens. But it is nowhere near enough for adults over 60 to rely on sunscreen-free sun exposure as their primary vitamin D source. The solution is not to abandon sun protection. It is to use food and supplements as your main supply, and treat any incidental sun exposure as a small bonus.

How does aging change the way skin makes vitamin D?

Your skin contains a compound called 7-dehydrocholesterol, which UVB light converts into the precursor to vitamin D. As we age, concentrations of this compound in the skin decline significantly. Research published in the American Journal of Clinical Nutrition found that adults over 70 have roughly 75% less of this precursor in their skin than young adults. That means even an hour of unprotected midday sun in July may not produce meaningful vitamin D for someone in their 60s or 70s.

Skin tone also plays a role. Melanin — the pigment that gives skin its colour — acts as a natural sun filter. People with darker skin tones need significantly more sun exposure to produce the same amount of vitamin D, which means deficiency risk is even higher for older adults with deeper complexions.

Does where you live affect summer vitamin D levels?

Absolutely. UVB rays only reach the earth’s surface at a steep enough angle to trigger vitamin D synthesis when the sun is high in the sky — generally between 10am and 3pm, and only when you’re close enough to the equator. If you live above roughly 35 degrees north latitude (that covers most of the UK, Canada, and the northern United States), meaningful UVB synthesis is limited even in summer, and essentially impossible from October through March.

Cloud cover cuts UVB by 50–60% on an overcast day. Spending time indoors near a sunny window doesn’t help either — standard glass filters out virtually all UVB while letting through the UVA rays that cause skin ageing and DNA damage. So a sunny afternoon working near a window gives you warmth and glare but almost no vitamin D benefit.

Which vitamins and supplements do seniors actually need?

Vitamin D is consistently one of the most important supplements for adults over 60. Most health authorities recommend between 800 and 2,000 IU (international units) of vitamin D3 daily for older adults, with some researchers arguing that 2,000 IU is the more protective dose. Vitamin D3 (cholecalciferol) is better absorbed than the D2 form, so look for D3 on the label.

Vitamin D rarely works alone — it needs magnesium to convert into its active form, and it works alongside vitamin K2 to direct calcium into bones rather than arteries. If you are taking a higher-dose vitamin D supplement, a combined D3/K2 product or a separate magnesium supplement (glycinate or malate are gentle on digestion) is worth considering. Always check with your doctor before starting supplements, particularly if you take blood thinners or have kidney disease, as vitamin D can interact with these conditions.

Beyond vitamin D, the supplements with the strongest evidence for adults over 60 include vitamin B12 (absorption declines with age), omega-3 fatty acids for heart and brain health, and calcium from food sources rather than high-dose supplements. A simple blood test — a 25-hydroxyvitamin D test — tells you exactly where your levels stand and removes the guesswork.

What foods are highest in vitamin D?

Vitamin D is one of the hardest nutrients to get from diet alone, which is part of why deficiency is so common. The best dietary sources are:

  • Oily fish — salmon, mackerel, sardines, and trout are the richest sources, with a 100g serving of wild salmon providing around 600–1,000 IU
  • Egg yolks — a useful but modest source, providing around 40 IU per yolk
  • Fortified foods — many milks, plant-based milks, cereals, and orange juices are fortified with vitamin D; check the label for amounts
  • Mushrooms — particularly those exposed to UV light (some products are now labelled as such); they can provide meaningful D2
  • Cod liver oil — a traditional source, high in vitamin D and omega-3s, though also high in vitamin A so use as directed

For most adults over 60, a combination of dietary sources plus a daily supplement of 1,000–2,000 IU D3 is the most reliable way to keep levels in a healthy range year-round — regardless of season.

How does vitamin D connect to sleep, pain, and healthy ageing overall?

Low vitamin D is linked to a surprising range of issues that matter deeply to people over 60. Research connects deficiency to poor sleep quality, with studies showing that adequate vitamin D supports the regulation of sleep hormones. If you are among the many older adults looking for ways to improve sleep quality naturally, checking your vitamin D level is a sensible first step.

Vitamin D receptors exist in muscle and nerve tissue, which is why deficiency often shows up as diffuse muscle aches and bone pain — symptoms sometimes mistaken for arthritis or fibromyalgia. For seniors managing chronic pain without opioids, correcting a vitamin D deficiency won’t eliminate pain, but it can meaningfully reduce the musculoskeletal aching that compounds other conditions. It also plays a role in immune function, mood regulation, and preserving muscle mass — the last of which is critical for staying mobile and independent as we age.

The best diet for healthy ageing is one that takes vitamin D seriously: rich in oily fish, eggs, and fortified foods, supported by a sensible daily supplement, and paired with whatever safe, effective exercise you enjoy — whether that’s walking, swimming, resistance bands, or yoga, all of which are excellent options for adults over 60.

Summer is not a vitamin D safety net. But once you know that, you can stop assuming you’re covered and start making sure you actually are.

Frequently Asked Questions

Can I get enough vitamin D from summer sun if I don’t wear sunscreen?

For adults over 60, probably not reliably. Older skin produces roughly 75% less vitamin D from sunlight than younger skin, so even unprotected midday sun exposure often fails to raise levels adequately. A daily D3 supplement of 1,000–2,000 IU, confirmed by a blood test, is a safer and more consistent approach than skipping sun protection.

Which vitamins and supplements do seniors actually need?

The strongest evidence for adults over 60 supports vitamin D3, vitamin B12, and omega-3 fatty acids. Magnesium and vitamin K2 are useful companions to vitamin D. Rather than taking a large stack of supplements, ask your doctor for a blood test to identify any actual deficiencies before spending money on pills you may not need.

How can older adults improve sleep quality naturally?

Correcting low vitamin D is one underappreciated step, as vitamin D supports sleep hormone regulation. Beyond that, consistent sleep and wake times, limiting screen light in the hour before bed, cooler bedroom temperatures, and gentle evening exercise like walking or stretching all have good evidence behind them for improving sleep in adults over 60.

What exercises are safe and effective for adults over 60?

Walking, swimming, cycling, resistance band training, yoga, and tai chi are all well-supported options for older adults. The ideal combination includes some aerobic activity (for heart health), resistance work (to preserve muscle and bone density), and balance training (to reduce fall risk). Always start gradually and consult your doctor if you have joint, heart, or balance concerns.

How can seniors manage chronic pain without opioids?

A multi-pronged approach works best: correcting nutritional deficiencies like vitamin D, gentle movement therapies such as aqua aerobics or yoga, anti-inflammatory dietary patterns (like the Mediterranean diet), cognitive behavioural therapy for pain, and topical treatments like diclofenac gel for localised joint pain. Always work with your healthcare provider to build a personalised plan.