When Sara Corday, 32, first found out she had a vitamin D deficiency she was shocked. She spends her summers at the beach, cycles and loves to spend time outdoors. She has never worn sunblock or used sun protective clothing.

The body starts to produce vitamin D known as the ‘sunshine vitamin’ when ultraviolet B rays hit the skin. Vitamin D, is responsible for muscle development and bone health, among other things. A deficiency of this vitamin is strongly linked to osteoporosis, a medical condition in which the bones become brittle and fragile from loss of tissue. Researchers also now think there is a possible link between vitamin D and cardiovascular disease, diabetes and some cancers.

“I originally went to the doctor complaining of heart palpations,” said Miss Corday, who is the Development and Volunteer Coordinator at the Society for Prevention of Cruelty to Animals (SPCA). “The doctor ordered a full blood panel.”

She was relieved but surprised when she received the diagnosis.

“The doctor said that it wasn’t anything too serious just something that needs to be addressed,” said Miss Corday. “I felt better, but I was shocked when she said vitamin D deficiency because I have never avoided the sun.”

But Dr Janet Daly dermatologist with the Bermuda Skin Cancer Foundation said the idea that people produce a lot of vitamin D through sun exposure is actually a bit of a myth. She often sees clients who have both skin cancer resulting from sun exposure, and osteoporosis related to a vitamin D deficiency.

“The truth is adults don’t produce that much vitamin D through exposure to ultraviolet light,” Dr Daly said.

Miss Corday said, since the diagnosis, she is taking a vitamin supplement and trying to eat more vitamin D rich foods.

“Vitamin D is a tricky one because it isn’t found in too many foods naturally, foods that I like anyway,” she said. “I’m not very fond of fish, soy or milk. That could be why I have the deficiency to begin with. The main foods that have vitamin D that I can handle are eggs, cheese and mushrooms. Mushroom omelette anyone?

“It’s a little hard to get vitamin D from the sun when you were diagnosed at the beginning of December so I’m hoping the supplements and mushroom omelettes help before I am retested in April.”

Dr Daly, however, warned that exposing your skin to more ultraviolet light, is not the answer to such a diagnosis. There are better ways to increase your levels.

“Through prolonged exposure to the sun, you can develop skin cancer more than you may raise your vitamin D levels,” she warned.

She said the best way to increase it is to take vitamin D supplements, as Miss Corday is doing, and to eat foods rich in it, such as wild salmon and egg yolks.

“Eat fish once a week,” she said. “A wild caught fatty salmon fillet is especially good. If adults sun themselves the skin does produce the precursor to vitamin D but it takes a long time for various organs in the body including the kidney and liver to produce it. In contrast, eating something like a fatty piece of salmon or a chicken liver, will deliver the vitamin D straight to the liver where it is stored and released directly from the liver as your body calls for the vitamin D. Vitamin D can be found in any milk, egg or animal product. It is a fat soluble vitamin.”

Dr Daly said the number of people being diagnosed with vitamin D may have increased lately as the standards for how much vitamin D a person should have in their system has been raised. The increase has not been without controversy.

Some researchers have cast doubt on the prevailing wisdom that vitamin D supplements can prevent conditions like cancer, diabetes and heart disease, saying that low vitamin D may be a consequence, not a cause, of ill health.

Dr Daly said there is some suggestion that the standards were raised due to pressure from the tanning bed industry, which benefits from an increased interest in catching ultraviolet light, especially in colder climates. She was doubtful of the research behind raising the vitamin D standard and said it was done mostly to be on the safe side.

“In the future, you may see the medical community drop the recommended vitamin D levels again,” Dr Daly said.

She thought another factor that could be contributing to more people being diagnosed with a vitamin D deficiency was an increased focus on low fat, heart healthy diets.

“Yet, ancient indigenous Eskimo populations ate whale, seal, and fish ­­— fat-rich ocean diets, which provided them with massive amounts of vitamin D,” she said. “Their hearts remained healthy. Liver and hormonal systems in Eskimo populations must have been capable of adapting to these very high vitamin D consumption levels, so ocean fat sources can be considered the very healthiest to eat for both heart health and for providing vitamin D to meet our body’s needs.”

Although anyone can develop a vitamin D deficiency, new research is finding that people with darker skin are actually a little more vulnerable to it. The pigment melanin reduces the skin’s ability to make vitamin D in response to sunlight exposure. Some studies show that older adults with darker skin are at high risk of vitamin D deficiency. Vegetarians, vegans and people who eat less animal products and byproducts are also at risk and are advised to ask their doctor about taking a vitamin D supplement.