In a sunny country like Australia, you’d be forgiven for thinking that everybody gets enough vitamin D.
However, according to the , around one in four Australian adults live with some form of vitamin D deficiency. Inadequate vitamin D levels can cause rickets (due to a calcium deficiency), and an increased risk of bowel cancer, heart disease, infections and autoimmune diseases.
Why you might be vitamin D deficient
If you’re living with a vitamin D deficiency, you may assume that you’re either not getting enough sun or eating the right kinds of vitamin D-rich foods.
However, there may be another reason. A spokesperson for , explains that the colour of your skin may also be influencing your vitamin D levels.
People with more melanin in their skin [have darker skin and] require more vitamin D than others.
Melanin is the substance in the skin that makes it dark. “People with more melanin in their skin [have darker skin and] require more vitamin D than others,” says McGrice, an accredited practising dietitian at
explains that melanin seemingly ‘competes" for UVB with the substance in the skin that kick-starts the body's vitamin D production. As a result, people with darker skin usually need more UVB exposure than light-skinned people to ascertain the same amount of vitamin D.
Other cultural considerations also come into play. “Individuals who cover more of their skin (they may wear veils for religious purposes) may also have an increased risk of vitamin D deficiency due to reduced exposure to sunlight.”
The best sources of vitamin D
When you have a vitamin D deficiency, the easy fix is to go on supplements. estimates that one in twenty Australian adults take vitamin D tablets. McGrice says while vitamin D supplements have their place in replenishing nutrient levels, the two best ways to maintain a healthy level of vitamin D are through safe sun exposure and diet.
“Although it is possible to meet our vitamin D requirements through food, it’s challenging to do so. There are not a lot of foods available that contain high levels of vitamin D. However, once you know the foods that are rich sources, you can modify your diet accordingly.”
Here are some of the richest dietary sources of vitamin D.
Fish
“Salmon is a really nutritious food and it's also a great source of vitamin D,” she says. “A 100 g serving of salmon provides around 526 international units of vitamin D, which is around 135 per cent of your daily recommended requirement.”
Herring, sardines and tuna are also rich in vitamin D. “Tuna, sardines and herring have 150 to 200 international units of vitamin D. So although that’s high, it’s still less than half of the amount found in salmon.”
When you consider how rich salmon is in vitamin D, it feels like a simple fix to hit your daily targets by eating salmon regularly. However, there is one catch.
“You can’t eat salmon every day of the week because of its mercury levels. The recommendations state that you should only eat fish two-to-three times a week.
“Salmon is certainly a lower mercury fish compared to other varieties, so if somebody wanted to have salmon three times a week, I wouldn't have any problems with that. But I don’t recommend having it every day.”
Eggs and dairy
McGrice claims that one egg has around 50 international vitamin D units, equating to about 10 per cent of your daily requirement.
“If you have two eggs, you’ll be getting a good dose of vitamin D. But eggs alone will not completely provide you with all the vitamin D you need.
“Dairy is another good source. It has around 100 international units per serve, so that would provide you with 30 per cent of the recommended daily amount.”
Fortified foods
There are several foods available that are fortified with vitamin D to make life a lot easier. Some of these include orange juice, milk, bread, soy drinks, breakfast cereals and margarine.
If you opt to eat foods fortified with vitamin D, make sure you check to see what other ingredients it contains like fats, sugar and additives.
Offal
Organ meats are not only more tender than other cuts of meats, they usually offer more vitamin D.
Beef livers are a popular traditional choice for people looking to boost their vitamin D levels. However, a journal article from shows that the highest vitamin D concentrations may be found in kidney meat, while the lowest concentration exists in muscle meat.
Mushrooms
Mushrooms are one of the richest food sources of vitamin D. “When mushrooms are exposed to sunlight, they actually convert that sunlight into vitamin D. So when we consume a sunlight-exposed mushroom, we also consume and absorb its vitamin D content.”
McGrice estimates that 100 grams of white mushrooms that have been exposed to sunlight will contain over 1000 international units of vitamin D – that’s around 260 per cent of your recommended daily intake.
The good news is that it’s hard to ever eat too many sunlight-exposed mushrooms. “Mushrooms are a food you can have every day to meet your vitamin D requirements. You just have to make sure they are sunlight-exposed.”
