Here, we speak to Dr. Ginni Mansberg about vitamin D deficiency, safe time in the sun, and absorbing vitamin D in our diet.
It’s that time of year again - when we’re faced with the dilemma of wanting to spend long summer afternoons outdoors, but need to play safe and avoid the Australian summer sun’s harshest and most dangerous rays.
Adding to that dilemma now is the idea of vitamin D deficiency. Vitamin D has been proved to be a vital chemical element for our general health and well-being, which - as a sort of catch 22 - happens to be detracted and absorbed by the light of the sun.
Australia has one of the largest rates of melanoma in the world – and sun safety is undoubtedly extremely important, especially throughout hot summer months.
However, when 1 in 4 Australians are said to have vitamin D deficiencies, and it's linked to health issues like osteoporosis, diabetes, heart and pregnancy problems, it’s important to ensure we are getting our fix in a safe, regular manner.
We asked Dr. Ginni to give us the facts about vitamin D, and how we can go about upping our intake without harm.
So what is vitamin D, and why is it important for us?
Although Vitamin D is called a vitamin, it’s technically a chemical! It is essential for health and must be transformed by the body before it can do us any good.
Vitamin D is important as it helps our body to perform natural bodily functions. It helps you to absorb calcium and without vitamin D, the body can only absorb a small portion of the calcium from your standard diet. Recent studies also show us that vitamin D is critical for functions in the heart, blood vessels, muscles and glands.
What happens when we have a vitamin D deficiency?
Vitamin D deficiency is a really serious issue and has been linked to a range of health problems.
Although not conclusive causation data, this includes osteoporosis (brittle bones) and osteoporotic fractures; Alzheimer’s disease and all other causes of dementia; muscle and bone aches and pains; more heart attacks, heart failures, and strokes; diabetes; osteoarthritis; and pregnancy problems including gestational diabetes, low APGAR scores for the newborn, weight gain in pregnancy, pre-eclampsia, preterm birth and low birth weight baby.
It’s also been linked to types of cancer. Vitamin D deficiency might be causal in some prostate, kidney, pancreas, and breast and bowel cancers. A 2006 Harvard study of men found that a 10 ng/ml increase in blood levels of vitamin D is linked to a 17% reduction in the risk of developing cancer and a 29% lower chance of dying from cancer.
And what is the standard for stating that someone has a deficiency?
To determine your vitamin d levels, you would need a blood test and the definition of a Vitamin D deficiency on a blood test is <50nmol/L.
It’s still so important to apply sunscreen rigorously during summer. However, a number of Australians are now aware of the concept of vitamin D deficiency, and see regular sunscreen use as a way of stopping them from getting enough vitamin D. What do you think?
I think that it is all about balance. Australians have some of the highest melanoma rates in the world, and so sun safety is a very, very important issue.
How much time should we spend in the sun per day, and does it change person-to-person?
Ultimately our body creates vitamin D when we absorb UVB rays (the specific ultraviolet rays from the sun that burn you and cause most skin cancers!). There is a loose formula we can use to work out roughly the time you need to be exposed to UVB rays to maintain your vitamin D levels, which is one-third of someone’s personal burn time per day.
We need to keep in mind that it’s different for different people and in different times/locations. For example, because of my fair skin, I will burn within five minutes in an Australian summer, but I’ll likely not burn for at least 60 minutes in Europe during winter.
What sorts of food are rich in vitamin D? And do you think it’s really possible to increase our vitamin D levels through diet?
There are plenty of foods that provide vitamin D, including oily fish and egg yolks. Some food companies are also now being fortified with added vitamin D and if you hunt them out, they can be a nice daily boost.
For example, Special K cereals now also contain Vitamin D to help provide a little of the sunshine nutrient in your breakfast bowl.
Fortified foods consumed in parallel with a few lifestyle changes including a lunchtime walk with your sleeves rolled up or outdoor activity on the weekend is something within reach for each individual and will make all the difference.