Vitamin D
Vitamin D is one of the 4 fat–soluble vitamins needed in our bodies for good health.
It is most well known for being important in making sure our bones are formed well and stay strong throughout our lives. In fact, it was the role of vitamin D in the prevention and treatment of the bone disease Rickets in children that led to its discovery early in the 20th Century. While vitamin D is officially a vitamin, it works more like a hormone in our body, making sure that we have just the right balance of calcium between our bones and in our blood. It can work to deposit calcium in our bones to store for later when we need it, and also signal to our body to release calcium into the blood to make sure we always have just the right amount. Vitamin D is also important for the health of many other body systems. One of the main roles vitamin D plays in our body has to do with healthy cell differentiation, which means that it is important for healthy growth in children and healthy ageing in adults, and it can play a role in preventing cancer cells from developing. It’s important for a healthy immune system, making sure that our body will effectively fight against infections and invasion, but in a way that prevents and controls chronic inflammation. Vitamin D is an important component of the hormonal system that controls our blood pressure. Therefore, it plays an important supportive role in our cardiovascular health. And it is thought that it protects the B–cells of the pancreas, and with the role it plays in the production of insulin, as well as controlling inflammation, may make it a part of preventing type 2 diabetes. Dietary sources of vitamin D include fish (especially oily fish such as salmon, tuna and sardines), eggs and dairy foods. Mushrooms can be a plant–based source of vitamin D, but the amounts and the body’s ability to absorb the vitamin D from plants is much less than from animal sources. Any vitamin D that we may get from our food is absorbed in
20
ON T H E C OA S T – FA M ILIES
HOW TO HAVE FUN IN THE SUN! BY CHRISTINA BATEY, DIETITIAN
the jejunum, which is the middle section of our small intestine. It’s very hard for most people to consume enough vitamin D through their diet, because the most absorption that most people will get from their food is about 50% of available vitamin D in food. However, if you are elderly, have had surgery, or you have other conditions that may affect the jejunum, such as Coeliac Disease, Inflammatory Bowel Disease, Cancer, certain skin conditions like severe eczema, your ability to absorb the sun’s UV rays and make vitamin D will be reduced, and you may need to rely on getting vitamin D from the foods you eat or a supplement. Thankfully, there is another way we can make vitamin D, and we don’t have to eat a thing! You may have heard that you can “get vitamin D from the sun”. This is a very simplified way to describe it, but it is essentially true! Naturally occurring chemicals in our skin change their structure when they are exposed to ultra violet rays in sunlight. This change of structure results in a form of vitamin D that our body can use. With such a sun–drenched country as Australia, you would think that vitamin D deficiency is not really something we need to worry about. Surprisingly, vitamin D deficiency is common, not only because of the way it goes hand–in–hand with other conditions in the jejunum, but also because of how careful we have all become about our sun exposure. Other factors also affect our ability to make vitamin D from the sun, such as our natural skin colour, our age, our mobility and some medications. To ensure you are making vitamin D, exposure needs to be on to bare skin, from a direct source of light from the sun. The components of the sunlight that
help us make the vitamin D cannot pass through glass, so sitting next to a window will not work. The form of vitamin D that comes from the sun is more readily absorbed in the body and only a short exposure is needed to get what your body needs. In our region about 15 minutes per day in summer or 30 minutes per day in winter wearing shorts and t–shirt will give you your daily of vitamin D. You may need to soak up more rays if you are more covered up, are older, have health conditions that impact vitamin D absorption and creation, have darker skin or do not go outside every day. With one of the highest rates of skin cancer in the world, it’s important we have good management of our sun exposure. The Cancer Council has some great guidelines on getting optimal sun for vitamin D production without putting ourselves at unnecessary risk. You can find the UV index for the day by looking up your favourite weather information service. If the UV rating is 3 or higher, prioritise sun protection, and only have minimal time in the sun. When the UV rating is below 3, go outdoors in the middle of the day and spend time in the sun. With the last few seasons of rainy weather, it is likely you may not have gone outside to receive your daily dose of vitamin D. If you are concerned that your vitamin D levels are low, you are at risk of osteoporosis or feel your mood is lower than usual, your vitamin D levels may be low and it is recommended you ask your GP for a blood test to check your levels and prescribe supplementation if required. Your dietitian can also assess your food intake and support you in implementing strategies for making sure you are getting enough vitamin D through a balanced diet considering your individual health needs.
Christina Batey is an Accredited Practising Dietitian at Bright Diets. As a busy wife and mother to three children she understands how difficult it can be to ensure the family eats that healthy balanced diet we all strive for. She loves helping people overcome the challenges with juggling the demands of life and ensuring everyone in the family has a balanced diet and lifestyle helping them lead happier and healthier lives. You can contact Christina on 0421 199 669 or via www.brightdiets.com.au or connect on Bright Diets Facebook page.
