What is vitamin D?

Vitamin D from food is a fat-soluble vitamin. That means it can be stored in your body.

Vitamin D comes in 2 forms:

1. vitamin D2 (ergocalciferol)
2. vitamin D3 (cholecalciferol)

Some foods have extra vitamin D added during processing to increase their health benefits — these are known as ‘fortified’ foods.

Vitamin D2 comes from plant sources. It's also found in:

• fortified foods — such as some fortified milks and margarines
• some supplements

Vitamin D3 is made in your skin when you are exposed to sunlight. It's also found in some animal foods and supplements.

Vitamin D needs to be activated and turned into a hormone to work effectively. This is done in your liver and kidneys.

Why is vitamin D important for my health?

Vitamin D is important for your health.

Vitamin D helps your body absorb calcium from the food you eat. This is vital for bone development and strength. It also helps control the amount of calcium in your blood.

Vitamin D is also important for the health of your:

• immune system
• skin
• muscles
• brain

A lack of vitamin D can increase your risk of certain conditions, such as:

• osteoporosis
• osteomalacia (softening of the bone)
• type 2 diabetes
• high blood pressure
• infectious diseases, including severe infection with COVID-19

What are the natural sources of vitamin D?

It is almost impossible to get enough vitamin D from food alone. In Australia, most people can get enough vitamin D with careful sun exposure.

Exposure to sunlight

The main source of vitamin D comes from your skin being exposed to ultraviolet (UV) radiation from the sun. Most Australians meet their vitamin D needs from exposure to the sun.

How much time you should spend in the sun will depend on:

• your skin tone — naturally dark-skinned people need more UV exposure to make enough vitamin D
• the amount of skin you expose
• where you are in Australia
• the season — time of year
• the time of day

You need to balance the need for some sun exposure to make vitamin D with the risk of skin damage from the sun. If UV radiation is high (the UV index is 3 or above), it's important to wear protection to reduce your risk of skin cancer.

In general, during summer in Australia, you only need to spend a few minutes outdoors on most days to get enough vitamin D. For many people, this will be achieved through incidental sun exposure during normal daily outdoor activities.

In most southern states in Australia during winter, it's possible to keep up your vitamin D levels by spending time outdoors with sufficient skin exposed during the middle of the day.

See the sunshine map to see how much sun exposure you need where you are in Australia.

Foods high in vitamin D

While vitamin D is found in some food, it's in small amounts. Few foods are rich in vitamin D.

Some foods are fortified with vitamin D (they have added vitamin D). In Australia, vitamin D fortification is mandated for all margarine. Check the food label to see if there is added vitamin D.

How much vitamin D do I need from food?

The Australian Government publishes recommended dietary intakes (RDIs) for all vitamins. The recommended amount of vitamin D from food depends on your age.

• Babies, children, teenagers and adults aged 19 to 50 years should have 5μg of vitamin D a day.
• Adults aged 51 to 70 years should have 10μg of vitamin D a day.
• Adults aged over 70 years should have 15μg of vitamin D a day.

What happens if I have too much vitamin D?

There is no negative effect of excess vitamin D from the sun. But extended exposure to harmful UV radiation does dramatically increase your risk of skin cancer.

Should I take vitamin D supplements?

If your doctor says you are low in vitamin D, you might need a vitamin D supplement.

Can taking vitamin D supplements cause side effects?

Taking too much of any medicine or supplement has risks.

People with certain conditions should not take vitamin D supplements.

Vitamin D supplements rarely cause vitamin D toxicity. This can lead to hypercalcaemia (where there is too much calcium in your blood).

Before taking any vitamin supplement, speak with your doctor, pharmacist or an accredited dietitian. While vitamins can supplement your diet, they should not be used as a replacement for a healthy lifestyle.

If you are concerned that you have taken too much of a vitamin D supplement, call the Poisons Information Centre (13 11 26).

Resources and support

See the Australian Guide to Healthy Eating.

Dietitians Australia has information on healthy eating and finding a dietitian.

The Cancer Council's SunSmart app can help you check your daily local sun protection times.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with you 24 hours a day, 7 days a week.

Languages other than English

NSW Health has a factsheet about vitamin D and information about eating healthy in languages other than English.

Information for Aboriginal and/or Torres Strait Islander peoples

Australian Indigenous HealthInfoNet has many resources about healthy eating for Aboriginal and/or Torres Strait Islander peoples.