Myth: We get all the vitamin D we need from the sun.
Fact: My mother was recently told she had low vitamin D levels. I was quite surprised as she is an active lady who loves the outdoors and spending time in her garden. Living in a sunny country like Australia, surely she gets enough ‘sunshine vitamin’? Looking into this subject further, I discovered low vitamin D levels are a real problem for many people, especially older people whose skin is less efficient at making vitamin D from sunshine. People over 70 need three times as much vitamin D as those under 50.
The risk also increases in those living in less sunny climates, those with dark skin, those who don’t expose their skin to the sun for religious reasons, and those who always wear high protection sunscreen. My mother’s low vitamin D levels are now starting to make sense – she has taken skin cancer prevention very much on board and never goes outside without sunscreen, a long sleeved shirt and a hat. Low vitamin D levels are also passed on from mother to baby as vitamin D deficient mothers make vitamin D deficient breastmilk. Also of interest is that obese people are more likely to have low vitamin D because it is fat-soluble vitamin and gets trapped in body fat unable to travel around the body to where it is needed.
What does vitamin D do? It is vital for metabolising calcium and strong bones. In fact my mother’s vitamin D status was discovered after she broke a rib, albeit as a result of falling off a ladder! But the magic of vitamin D doesn’t end with bones. It is implicated in protection against cancer, Parkinson’s disease and high blood pressure; regulating the immune system; insulin secretion and blood glucose control. Research has also found a strong correlation between higher vitamin D levels and HDL (good) cholesterol levels. A recent study also found a link between low vitamin D levels and depression suggesting the potential for more vitamin D to boost mood – giving new support for the idea of a ‘sunny disposition’.
Vitamin D deficiency requires supplementation to correct, but how can it be prevented? It makes sense to get some sunshine each day if possible, but dietary sources have taken on renewed importance – especially in countries like Australia where skin cancer incidence is high. Foods containing vitamin D include some fatty fish (mackerel, salmon, sardines) and fish liver oils, as well as small amounts in liver, cheese and eggs. In the US, milk is fortified with vitamin D but in Australia, vitamin D is added only to some brands of dairy foods and milk alternatives (eg, soy milk). All margarine spreads in Australia and some in the US have vitamin D added making them good to include for general good health as well as healthier cholesterol levels. You can check the label to ensure minimal trans-fat levels.
Nicole Senior is author of Eat to Beat Cholesterol and Heart Food available online.
For more information on nutrition and heart health visit www.eattobeatcholesterol.com.au