With so many different vitamins and minerals we need to consume in order to stay healthy, it's easy to become overwhelmed.
While a healthy, varied, plant-filled diet can help take care of our nutrient requirements, there's one vitamin that needs a bit of extra attention -- vitamin D.
"Vitamin D is really interesting because it actually acts like a hormone, rather than a vitamin," accredited practising dietitian, Chloe McLeod, told The Huffington Post Australia.
"It has a number of key roles in the body. Firstly, its role in bone health through absorption of calcium and phosphorus means that it's an important component of the health of your bones and teeth."
Some research has suggested vitamin D is protective against a number of different medical conditions, including cardiovascular disease, some cancers and diabetes.
What is vitamin D?
Vitamin D forms in the skin when it is exposed to UV from sunlight. It can also be obtained from some foods. We need vitamin D to maintain good health and to keep bones and muscles strong and healthy.
How much sun do we need for healthy bones?
The best source of vitamin D is UVB radiation from the sun. UV radiation levels vary depending on location, time of year, time of day, cloud coverage and the environment.
For most people, adequate vitamin D levels are reached through regular incidental exposure to the sun. When the UV Index is 3 or above (such as during summer), most people maintain adequate vitamin D levels just by spending a few minutes outdoors on most days of the week.
In late autumn and winter in some southern parts of Australia, when the UV Index falls below 3, spend time outdoors in the middle of the day with some skin uncovered. Being physically active (e.g. gardening or going for a brisk walk) also helps boost vitamin D levels.
"However, there is some other research saying the benefits have been somewhat overstated, but at the same time, I think it is too important to miss given how many people in our population are vitamin D deficient," McLeod said.
"The Australian Bureau of Statistics are saying around one in four Australian adults are vitamin D deficient, with around seven percent having moderate deficiency, which is still a lot."
When people are deficient in vitamin D, it can affect bone, mental and immune health.
"Growing pain, frequent fractures, muscle weakness and soft bones are all linked to vitamin D deficiency, so it all comes back to bone health," McLeod said.
According to McLeod, one of the main reasons why Australians aren't getting enough vitamin D is because we're simply not spending enough time in the sun. It doesn't help that many Australians sit in an office all day, away from the sunlight, for their job.
"We are inside a lot more of the time, and we don't spend as much time outdoors," McLeod said.
"Also, skin colour can make a difference. People with darker skin don't absorb or make as much vitamin D as people with fairer skin. There's many different things that can play a role."
Getting sunshine each day is the easiest way to obtain vitamin D, however there's one particular food that can help us meet the daily requirement.
"[Vitamin D deficiency] can be an easy thing to rectify," McLeod told HuffPost Australia. "A number of different foods contain vitamin D.
"My favourite thing to talk about is the mushrooms. There's science that shows if you put mushrooms in the sun for about an hour, then 100 grams of mushrooms will give you around 30 percent of your daily vitamin D needs.
"How cool is science? That's one of my favourite tips to suggest to people because it's so easy."
To use this trick, all you need to do is take the mushrooms out of the paper bag, put them on a tray in the sun, place them back in the paper bag after one hour, and store them in the fridge until you eat them.
"You can purchase vitamin D mushrooms in the supermarket if you would prefer, but they are a bit more expensive and you can easily do it yourself," McLeod said.
While some milks and eggs have been fortified with vitamin D, or naturally contain small amounts, it's not in large quantities in our food supply.
"Other than that, if you are low in vitamin D, it is a good idea to take a supplement. There's lots of different ones around," McLeod said. "Taking supplements means you're probably going to get your vitamin D levels up a bit quicker, and also spending that time in the sun.
If you think you have a vitamin D deficiency, check in with a GP or medical professional.
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