Vitamin D is essential for bone health, immune function and overall wellbeing. And it becomes even more crucial as we age.

New guidelines from the international Endocrine Society recommend people aged 75 and over should consider taking vitamin D supplements.

But why is vitamin D so important for older adults? And how much should they take?

Young people get most vitamin D from the sun

In Australia, it is possible for most people under 75 to get enough vitamin D from the sun throughout the year. For those who live in the top half of Australia – and for all of us during summer – we only need to have skin exposed to the sun for a few minutes on most days.

The body can only produce a certain amount of vitamin D at a time. So staying in the sun any longer than needed is not going to help increase your vitamin D levels, while it will increase your risk of skin cancer.

But it’s difficult for people aged over 75 to get enough vitamin D from a few minutes of sunshine, so the Endocrine Society recommends people get 800 IU (international units) of vitamin D a day from food or supplements.

Why you need more as you age

This is higher than the recommendation for younger adults, reflecting the increased needs and reduced ability of older bodies to produce and absorb vitamin D.

Overall, older adults also tend to have less exposure to sunlight, which is the primary source of natural vitamin D production. Older adults may spend more time indoors and wear more clothing when outdoors.

As we age, our skin also becomes less efficient at synthesising vitamin D from sunlight.

The kidneys and the liver, which help convert vitamin D into its active form, also lose some of their efficiency with age. This makes it harder for the body to maintain adequate levels of the vitamin.

All of this combined means older adults need more vitamin D.

Deficiency is common in older adults

Despite their higher needs for vitamin D, people over 75 may not get enough of it.

Studies have shown one in five older adults in Australia have vitamin D deficiency.

In higher-latitude parts of the world, such as the United Kingdom, almost half don’t reach sufficient levels.

This increased risk of deficiency is partly due to lifestyle factors, such as spending less time outdoors and insufficient dietary intakes of vitamin D.

It’s difficult to get enough vitamin D from food alone. Oily fish, eggs and some mushrooms are good sources of vitamin D, but few other foods contain much of the vitamin. While foods can be fortified with the vitamin D (margarine, some milk and cereals), these may not be readily available or be consumed in sufficient amounts to make a difference.

In some countries such as the United States, most of the dietary vitamin D comes from fortified products. However, in Australia, dietary intakes of vitamin D are typically very low because only a few foods are fortified with it.

Why vitamin D is so important as we age

Vitamin D helps the body absorb calcium, which is essential for maintaining bone density and strength. As we age, our bones become more fragile, increasing the risk of fractures and conditions like osteoporosis.

Keeping bones healthy is crucial. Studies have shown older people hospitalised with hip fractures are 3.5 times more likely to die in the next 12 months compared to people who aren’t injured.

Vitamin D may also help lower the risk of respiratory infections, which can be more serious in this age group.

There is also emerging evidence for other potential benefits, including better brain health. However, this requires more research.

According to the society’s systematic review, which summarises evidence from randomised controlled trials of vitamin D supplementation in humans, there is moderate evidence to suggest vitamin D supplementation can lower the risk of premature death.

The society estimates supplements can prevent six deaths per 1,000 people. When considering the uncertainty in the available evidence, the actual number could range from as many as 11 fewer deaths to no benefit at all.

Should we get our vitamin D levels tested?

The Endocrine Society’s guidelines suggest routine blood tests to measure vitamin D levels are not necessary for most healthy people over 75.

There is no clear evidence that regular testing provides significant benefits, unless the person has a specific medical condition that affects vitamin D metabolism, such as kidney disease or certain bone disorders.

Routine testing can also be expensive and inconvenient.

In most cases, the recommended approach to over-75s is to consider a daily supplement, without the need for testing.

You can also try to boost your vitamin D by adding fortified foods to your diet, which might lower the dose you need from supplementation.

Even if you’re getting a few minutes of sunlight a day, a daily vitamin D is still recommended.

Elina Hypponen, Professor of Nutritional and Genetic Epidemiology, University of South Australia and Joshua Sutherland, PhD Candidate – Nutrition and Genetic Epidemiology, University of South Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Australians have used commercial creams, lotions or gels to manage our skin’s sun exposure for nearly a century.

But why we do it, the preparations themselves, and whether they work, has changed over time.

In this short history of sunscreen in Australia, we look at how we’ve slathered, slopped and spritzed our skin for sometimes surprising reasons.

At first, suncreams helped you ‘tan with ease’

Sunscreens have been available in Australia since the 30s. Chemist Milton Blake made one of the first.

He used a kerosene heater to cook batches of “sunburn vanishing cream”, scented with French perfume.

His backyard business became H.A. Milton (Hamilton) Laboratories, which still makes sunscreens today.

Hamilton’s first cream claimed you could “
Sunbathe in Comfort and TAN with ease”. According to modern standards, it would have had an SPF (or sun protection factor) of 2.

The mirage of ‘safe tanning’

A tan was considered a “modern complexion” and for most of the 20th century, you might put something on your skin to help gain one. That’s when “safe tanning” (without burning) was thought possible.

Sunburn was known to be caused by the UVB component of ultraviolet (UV) light. UVA, however, was thought not to be involved in burning; it was just thought to darken the skin pigment melanin. So, medical authorities advised that by using a sunscreen that filtered out UVB, you could “safely tan” without burning.

But that was wrong.

From the 70s, medical research suggested UVA penetrated damagingly deep into the skin, causing ageing effects such as sunspots and wrinkles. And both UVA and UVB could cause skin cancer.

Sunscreens from the 80s sought to be “broad spectrum” – they filtered both UVB and UVA.

Researchers consequently recommended sunscreens for all skin tones, including for preventing sun damage in people with dark skin.

Delaying burning … or encouraging it?

Up to the 80s, sun preparations ranged from something that claimed to delay burning, to preparations that actively encouraged it to get that desirable tan – think, baby oil or coconut oil. Sun-worshippers even raided the kitchen cabinet, slicking olive oil on their skin.

One manufacturer’s “sun lotion” might effectively filter UVB; another’s merely basted you like a roast chicken.

Since labelling laws before the 80s didn’t require manufacturers to list the ingredients, it was often hard for consumers to tell which was which.

At last, SPF arrives to guide consumers

In the 70s, two Queensland researchers, Gordon Groves and Don Robertson, developed tests for sunscreens – sometimes experimenting on students or colleagues. They printed their ranking in the newspaper, which the public could use to choose a product.

An Australian sunscreen manufacturer then asked the federal health department to regulate the industry. The company wanted standard definitions to market their products, backed up by consistent lab testing methods.

In 1986, after years of consultation with manufacturers, researchers and consumers, Australian Standard AS2604 gave a specified a testing method, based on the Queensland researchers’ work. We also had a way of expressing how well sunscreens worked – the sun protection factor or SPF.

This is the ratio of how long it takes a fair-skinned person to burn using the product compared with how long it takes to burn without it. So a cream that protects the skin sufficiently so it takes 40 minutes to burn instead of 20 minutes has an SPF of 2.

Manufacturers liked SPF because businesses that invested in clever chemistry could distinguish themselves in marketing. Consumers liked SPF because it was easy to understand – the higher the number, the better the protection.

Australians, encouraged from 1981 by the Slip! Slop! Slap! nationwide skin cancer campaign, could now “slop” on a sunscreen knowing the degree of protection it offered.

How about skin cancer?

It wasn’t until 1999 that research proved that using sunscreen prevents skin cancer. Again, we have Queensland to thank, specifically the residents of Nambour. They took part in a trial for nearly five years, carried out by a research team led by Adele Green of the Queensland Institute of Medical Research. Using sunscreen daily over that time reduced rates of squamous cell carcinoma (a common form of skin cancer) by about 60%.

Follow-up studies in 2011 and 2013 showed regular sunscreen use almost halved the rate of melanoma and slowed skin ageing. But there was no impact on rates of basal cell carcinoma, another common skin cancer.

By then, researchers had shown sunscreen stopped sunburn, and stopping sunburn would prevent at least some types of skin cancer.

What’s in sunscreen today?

An effective sunscreen uses one or more active ingredients in a cream, lotion or gel. The active ingredient either works:

• “chemically” by absorbing UV and converting it to heat. Examples include PABA (para-aminobenzoic acid) and benzyl salicylate, or

• “physically” by blocking the UV, such as zinc oxide or titanium dioxide.

Physical blockers at first had limited cosmetic appeal because they were opaque pastes. (Think cricketers with zinc smeared on their noses.)

With microfine particle technology from the 90s, sunscreen manufacturers could then use a combination of chemical absorbers and physical blockers to achieve high degrees of sun protection in a cosmetically acceptable formulation.

Where now?

Australians have embraced sunscreen, but they still don’t apply enough or reapply often enough.

Although some people are concerned sunscreen will block the skin’s ability to make vitamin D this is unlikely. That’s because even SPF50 sunscreen doesn’t filter out all UVB.

There’s also concern about the active ingredients in sunscreen getting into the environment and whether their absorption by our bodies is a problem.

Sunscreens have evolved from something that at best offered mild protection to effective, easy-to-use products that stave off the harmful effects of UV. They’ve evolved from something only people with fair skin used to a product for anyone.

Remember, slopping on sunscreen is just one part of sun protection. Don’t forget to also slip (protective clothing), slap (hat), seek (shade) and slide (sunglasses).

Laura Dawes, Research Fellow in Medico-Legal History, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.