In the dark months of winter and still gray transition to spring, getting enough natural vitamin D through the sun's rays can be an almost impossible feat.

Vitamin D is produced under the skin by a reaction to the sun and is essential to regulating calcium and phosphate levels in the body. A lack of vitamin D can lead to bone softness and other complications. Low vitamin D levels can also lead to fatigue.

"Research also links vitamin D deficiency to increased risk of prostate, colon and breast cancer, as well as depression and cardiovascular disease," Kelly Hogan, clinical nutrition and wellness manager at Dubin Breast Center at Mount Sinai Hospital, told AccuWeather.

In the United States, vitamin D deficiencies can affect 85 percent of the population at latitudes above 37 degrees north, or areas above New Mexico, Texas and North Carolina, Hogan said.

The colder climate leads to a lack of exposure to sunshine.

Without perpetual sunshine, obtaining enough sunlight to keep the body content is difficult. While some physicians may recommend taking supplements, there are foods that can easily be incorporated into a person's diet to mitigate a lack of sun.

Vitamin D levels fall in the colder months as people see less sun exposure. (Yuko Yamada/iStock/Thinkstock)

"Skin production of vitamin D from sunlight is virtually non-existent in the winter," Dr. Sharon Orrange, associate professor of medicine at Keck School of Medicine at University of Southern California, told AccuWeather.

"It will be even harder for you to obtain enough vitamin D if you are dark skinned, obese, consistently use sunscreen or don’t absorb vitamin D well from your gut," she said.

Therefore, intake of foods fortified with vitamin D is even more important.

Few foods naturally contain vitamin D, but oily fish like sardines and salmon are exceptions, Orrange said.

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Vitamin D is also found in egg yolks, red meat, mushrooms and fortified foods like milk and orange juice. A regular intake of these foods may be enough to offset the lack of sunshine, but most experts recommend using a supplement.

While there is debate as to what kind of vitamin D supplement is best, incorporating one into a person's diet may prove beneficial.

Dr. Orrange said vitamin D3 is preferred as studies have shown the body absorbs it faster than other kinds.

Sun lamps and tanning beds are not recommended due to ultraviolet B radiation exposure.

"Because skin cancer is the most common form of cancer in the United States, it is not recommended that sun exposure be your form of vitamin D supplementation," Orrange said.

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