Often when we talk about sun exposure, there are discussions on balancing the need to protect ourselves against the harmful UV radiation from the sun against the need for adequate levels of vitamin D.

Worldwide, it’s estimated that 1 billion people are either deficient or not reaching sufficient levels of vitamin D. That being said, in Australia, we are lucky to enjoy more sunshine during the year than many other countries. We also know that some people are more at risk of being deficient than others.

As with any health topic, one of the best things that you can do is be fully informed of the risks and benefits so that you can take the best course of action for you and your family.

With that in mind, here’s everything you need to know about vitamin D.

What does it do?

Vitamin D is an important vitamin for general good health and wellbeing. One of its most important functions is to help the small intestine to absorb calcium from the diet. For this reason, vitamin D is especially important for maintaining healthy bones and teeth. It can help to prevent and treat conditions caused by inadequate bone formation and mineralization like rickets and osteomalacia.

Vitamin D also helps to support good immune health, possibly playing a role in protecting against some autoimmune diseases, such as multiple sclerosis, type 1 diabetes and cancer. There is also evidence that it may help to prevent and treat cardiovascular disease, the flu, and symptoms of depression, though further research is needed.

Vitamin D also helps to stimulate insulin secretion, helping to maintain glucose tolerance. Some studies have even suggested that it could help with weight loss, based on a reduction in appetite associated with calcium intake.

What is it found in?

Vitamin D has two main forms: the first is vitamin D2, known as ergocalciferol, which is found in plants and yeast and is commonly added to foods like margarine and bread.

The second is vitamin D3, which is also added to foods and found in fatty fish and eggs. Vitamin D3 is also known as the ‘sunshine vitamin’, as 80-90% of the body’s stores are from exposure to the sun.

How much do I need?

Vitamin D levels in the body are typically measured by nanomoles per litre, or nmol/L. According to the Australian Government Department of Health, Australian organisations typically consider levels lower than 50 nmol/L as suboptimal.

The Australian Health Survey 2011-12 found that 23% of Australians had vitamin D levels lower than 50 nmol/L.

The recommended daily adequate intake of vitamin D is Australia is:

● 5 micrograms (200 IU) for children, adolescents and adults aged 19-50 years,

● 10 micrograms (400 IU) for adults aged 51-70 years, and

● 15 micrograms (600 IU) for adults over 70.

However, it should be noted that these recommendations are based on no or minimal sunlight.

When it comes to how much time we need in the sun, this can vary between location, skin type, and season. Osteoporosis Australia recommends a few minutes on most days during summer (preferably early or late in the day) for all states and year-round for northern cities like Brisbane or Darwin. During the cooler months, 2-3 hours per week is recommended.

What are the risks of deficiency?

A severe vitamin D deficiency can lead to bone health issues, including conditions such as rickets or osteomalacia.

Other problems associated with not getting enough vitamin D are osteoporosis, fractures, cardiovascular disease, respiratory conditions, gastrointestinal problems, musculoskeletal conditions, and more.

There are some people who have a greater risk of health conditions resulting from a vitamin D deficiency. Older people, for example, are particularly vulnerable. This is because falls are a major health problem, and a vitamin D deficiency is associated with muscle weakness and a higher rate of falls. In fact, interventional studies have found that daily dosing of vitamin D was associated with a 20-30% reduction in fall rates.

Pregnant women are another group who are at risk. Low concentration of vitamin D is associated with the development of gestational diabetes. Vitamin D deficiencies are also related to a higher risk of complications including preeclampsia, cesarean section rate, low birth weight, and impaired skeletal, lung and immune development.

How do I know if I’m deficient?

Most Australians get a sufficient level of vitamin D during the summer. However, the prevalence of vitamin D levels lower than 50 nmol/L has shown to be higher in winter as there is less sunshine. This is especially the case for those living in the south-eastern states of Australia, including Victoria, the ACT and Tasmania.

Other people who are more likely to be deficient are:

● People with darker skin who require more UV exposure to produce vitamin D

● People who spend a lot of time indoors, such as people in nursing homes

● People taking particular medications

Should I take a supplement?

Whether or not you need to take a vitamin D supplement depends on a range of factors, and the answer will vary from person to person.

If you’re confused or need extra guidance, speak to your GP or visit your local Capital Chemist pharmacist for more information and advice.