Vitamin D and Sun Exposure in Australia: Getting the Balance Right
Australians hear a lot about covering up in the sun, and for good reason. Yet the sun is also how most of us get our vitamin D. That can leave people unsure how much sun is enough. The good news is that the two goals sit together better than you might expect.
This guide explains what vitamin D does and how your body makes it. It covers how to use the UV Index, who is more likely to run low and where food and supplements fit in. Everything here is general information drawn from Australian health sources.
What vitamin D does in the body
Vitamin D helps your body absorb calcium from food. That matters for building and keeping strong bones. It also helps control the amount of calcium in your blood. Healthdirect notes it supports your immune system, skin, muscles and brain as well.
Low levels can cause problems. According to healthdirect’s guide to vitamin D, low vitamin D can raise the risk of osteoporosis and osteomalacia, which is a softening of the bones. It has also been linked with type 2 diabetes and high blood pressure. These are good reasons to understand where your vitamin D comes from.
How your skin makes vitamin D
Your skin makes vitamin D when it is exposed to ultraviolet (UV) radiation from sunlight. For most Australians, this is the main source. Cancer Council Australia points out that UV radiation is also the main cause of skin cancer. So the same sunlight brings both a benefit and a risk.
The amount of sun you need is not the same for everyone. Healthdirect says it depends on your skin tone and how much skin is exposed. Where you live, the season and the time of day also make a difference. That is why a single rule of thumb does not suit every person or every month.
Using the UV Index as your guide
The UV Index is the simplest tool for getting the balance right. When it is 3 or above, Cancer Council advises sun protection to reduce the risk of skin cancer. At these levels, most people keep up their vitamin D with just a few minutes outdoors on most days. You do not need to sit in the sun for long periods.
You can check the UV Index in the weather section of the newspaper or on the Bureau of Meteorology website. The SunSmart app from Cancer Council also shows daily sun protection times for your area. No UV Alert is issued when levels are below 3. Checking each morning soon becomes a habit.
Winter and the southern states
In late autumn and winter, the UV Index in some southern parts of Australia stays below 3. In these conditions, Cancer Council’s vitamin D advice suggests spending time outdoors in the middle of the day with some skin uncovered. Being physically active also helps. Sun protection is not usually needed at these times.
There are exceptions to that winter advice. You still need protection at high altitude or near reflective surfaces like snow. The same applies if you work outdoors or spend long periods outside. A quick look at the UV Index before heading out will tell you where you stand.
Northern Australia and the summer months
Northern Australia has higher UV levels. Cancer Council says sun protection may be needed all year there, whenever the UV Index is 3 or higher. Early morning and late afternoon, when the index drops below 3, are considered safe without protection. That makes these times handy for a walk outside.
In summer, healthdirect notes that a few minutes outdoors on most days is often enough for many people. Long periods in strong sun raise the risk of skin cancer. Cancer Council is clear that overexposure to UV is never recommended, even for someone with low vitamin D. If you are worried about your levels, speak with your doctor instead of spending more time in the sun.
Does sunscreen stop you making vitamin D?
This is a common worry. Cancer Council says several studies show sunscreen has minimal impact on vitamin D levels over time. It also states that sensible sun protection does not put people at risk of vitamin D deficiency. So you can keep using sunscreen, a hat and shade on high UV days.
Many people put a lot of thought into the products they use on their skin. If that interests you, our post on skincare and beauty toxins looks at ingredients some people choose to avoid. Sun protection is still part of a sensible daily skin routine. Choose products you are happy to wear every day.
Who is more likely to have low vitamin D
Some people find it harder to make enough vitamin D from the sun. Cancer Council and healthdirect name several groups. People in these groups may want to talk with their doctor. The main ones are listed below.
- People with naturally darker skin, who need more UV exposure to make enough vitamin D
- People who cover their skin for religious or cultural reasons
- Older, frail or chronically ill people who spend most of their time indoors
- People living in care or other institutions
- People who are obese
- Babies of mothers with low vitamin D
- People taking certain medicines or with conditions that affect absorption
- People who avoid the sun because of a history or high risk of skin cancer
Spending most of the day indoors is a common thread in that list. Time at home can still be healthy, and simple things like sofa cleaning for your health help keep indoor spaces pleasant. For people living in care, access to outdoor areas and natural light is worth considering. Our post on furniture for a mental health facility touches on how these spaces are set up.
Food sources and supplements
Food helps, but it cannot do the whole job. Healthdirect says few foods contain much vitamin D, and it is almost impossible to get enough from food alone. Foods that do contain some include UV exposed mushrooms, oily fish such as salmon and anchovies, eggs and chicken. In Australia, all margarine must have vitamin D added.
Healthdirect lists recommended daily intakes from food. These are 5 micrograms for people up to 50, 10 micrograms for adults aged 51 to 70 and 15 micrograms for adults over 70. A dietitian can help you plan meals around foods like these. If you work with a nutrition professional, our post on nutrition coaching services looks at the business side of that field.
Supplements are only worth considering if your doctor says your vitamin D is low. Some people with certain health conditions should not take them. Too much vitamin D is rare but can cause too much calcium in the blood. Speak with your doctor, pharmacist or an accredited dietitian before starting any supplement.
Frequently asked questions
How much sun do I need for vitamin D?
When the UV Index is 3 or above, a few minutes outdoors on most days is enough for most people. In southern winters, when the index stays below 3, midday time outside with some skin uncovered helps. Needs vary with skin tone and location.
Should I skip sunscreen to get more vitamin D?
No. Cancer Council says sunscreen has minimal impact on vitamin D levels over time. Sensible sun protection does not put people at risk of deficiency. Overexposure to UV is never recommended.
Can I get enough vitamin D from food?
It is very hard to do. Healthdirect says few foods contain much vitamin D. Sunlight is the main source for most Australians.
Should I get my vitamin D tested?
If you are in a higher risk group or concerned about your levels, ask your doctor. They can tell you whether a blood test is worthwhile for you. Do not start supplements without advice.
This article is general information only and is not medical advice. Please speak with your doctor or a qualified health professional about your own health and vitamin D needs.