Vitamin D the “sunshine cure….” But, did you know Vitamin D is also in food?

Written by Melbourne Naturopath Bianca Potenta

It was called the “sunshine cure” and in the early 20th century, before the era of antibiotics, it was the only effective treatment for tuberculosis. No one knew why it worked, just that TB patients sent to rest in sunny places were often restored to health. In 1822 the same “sunshine cure” was discovered for the treatment of rickets, a deforming childhood condition caused by an inability by the body to make hardened bone.

In the past 25 years research has discovered Vitamin D has far greater functions than just building bones. We now know Vitamin D has a role in regulating over 1000 different genes in over 12 tissues and cells throughout the body, including the brain, pancreas, liver, intestines and immune cells. Helping to explain the extensive evidence that D has potent anticancer actions and serves as an important regulator of the immune system.

Many of Vitamin D’s health benefits increase when present in the bloodstream at levels considerably higher than those found in the Melbourne population, linking Vitamin D deficiency to many serious illnesses. Among them cancers, autoimmune conditions and even infectious diseases, such as influenza.
What’s concerning is the skin is the only tissue in the human body that can manufacture Vitamin D3 and occurs when the skin is exposed to ultra violet radiation (UVR) from the sun. However, living in Melbourne in the winter months creates a challenge for us Melburnians. The angle of the sun during Melbourne’s winter can significantly affect the skin’s ability to make Vitamin D. Not to mention the fact that cold weather tends to make us predominantly indoor lovers for at least 3 months of the year

BUT, did you know the “sunshine cure” is also found in food? People can obtain vitamin D from limited food sources, such as fatty fish, mushrooms and eggs. Below is a list of food sources that contain Vitamin D3 and D2.

Cod-liver oil (1 tbsp): 1,360 IU D3
Cooked tuna, sardines, mackerel or salmon (85–100g): 200–360 IU D3
Shiitake mushrooms (fresh, 100g oz): 100 IU D2 (dried, 100g oz): 1,600 IU D2
Egg yolk: 20 IU D3 or D2
Fortified dairy products, orange juice or cereals (one serving): 60–100 IU D3 or D2

In comparison, food provides a relatively small dose of D compared to the amounts made by the skin in response to sunlight. If someone with fair skin exposed their entire body to sunlight for 15 to 20 minutes in the middle of a summer day, it would equal a whopping 10,000IU of Vitamin D3. But, chances are exposing your body to the Melbourne summer sun at midday will result in some nasty sunburn.

Our advice to our fellow Melburnians… consider using food as medicine and consume a balanced diet that includes foods that contain vitamin D, particularly in the winter months, to reduce the dip in vitamin D levels that occurs during Melbourne’s winter. Get outdoors and be active on those sunny days at any time of the year, whilst still being sun smart, to ensure you get a big boost of vitamin D without the sun burn. If needed, have your vitamin D levels checked and speak to your healthcare if you are considering a Vitamin D supplement, including multivitamins containing Vitamin D.

If you are looking for a vitamin D rich recipe check out this delicious Shiitake Omelette. Perfect for breakfast, lunch or dinner.

References:
Holick MF 2002, ‘Vitamin D: the underappreciated D-lightful hormone that is important for skeletal and cellular health’, Current Opinion in Endocrinology & Diabetes, vol. 9, iss. 1, pp. 87–98

Nowson CA, McGrath JJ, Ebeling PR, Haikerwal A, Daly RM, Sanders KM, Seibel MJ & Mason RS 2012, ‘Vitamin D and health in adults in Australia and New Zealand: a position statement’, The Medical Journal of Australia, vol. 196, iss. 11, pp. 686–687

Tavera-Mendoza LE, White JH 2007, ‘Cell defences and the sunshine Vitamin’, Scientific American, Nov 2007, pp. 62-72.

VicHealth 2015, A study of UV and Vitamin D in Melbourne adults: Research summary, Victorian Health Promotion Foundation, Melbourne pp1-9.

Webb AR & Engelsen O 2006, ‘Calculated ultraviolet exposure levels for a healthy Vitamin D status’, Photochemistry and Photobiology, vol. 82, iss. 6, pp. 1697–1703

Webb AR, Kline L & Holick MF 1988, ‘Influence of season and latitude on the cutaneous synthesis of Vitamin D3: exposure to winter sunlight in Boston and Edmonton will not promote Vitamin D3 synthesis in human skin’, The Journal of Clinical Endocrinology & Metabolism, vol. 67, iss. 2, pp. 373–378

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