Getting Enough Vitamin D in Winter

You had planned to walk in your backyard garden this afternoon, with the winter sun enveloping you in a warm glow. But then, your plan is shattered by fast-approaching storm clouds. You seek shelter inside, just as rain lashes the windows.

So much for your vitamin D exposure for today, you think.

It’s true: winter weather often hampers the body’s opportunity for exposure to sunlight, a prime source of essential vitamin D, often called the sunshine vitamin. The timing of a lack of sun and vitamins is unfortunate, just as the cold and flu season takes hold.

Vitamin D is synthesized in the skin after exposure to the sun’s ultraviolet B (UVB) rays and is crucial for calcium absorption, which helps maintain strong, healthy bones. Sadly, deficiencies in vitamin D are common throughout the world and can lead to bones that are soft, weak, brittle and prone to fractures.

“It’s a challenge to get enough vitamin D in the winter,” said Phyllis Hogan, longtime owner of Winter Sun Trading Co. in downtown Flagstaff, an herbal apothecary. “The best form of vitamin D is, of course, sunshine. We should try to get at least 15 minutes at midday in direct sunlight; you need to expose your skin to natural sunlight, with particular attention to the legs and arms, but be mindful not to burn.”

Midday is best for exposure because the sun is the highest and its UVB rays are the most powerful.

As the winter months set in, many health care providers suggest supplementing vitamin D from the sun with vitamin D-3, which is more bio-available and absorbs more effectively than vitamin D-2. Hogan recommends combining vitamin D-3 with K-2, which “is great for absorption and bone health, as well as supporting the immune system.”

Lack of vitamin D can also leads to other health problems, in addition to weakened bones. “Researchers have found a deficiency in vitamin D is a risk factor for developing respiratory tract infection,” she said. “Vitamin D is a powerful immune factor for the respiratory tract. Lungs produce their own active form of vitamin D. I found that pretty interesting. Magnesium helps activate vitamin D. It’s a cofactor. Magnesium and K combined have a greater effect on vitamin D levels.”

She herself uses KAL vitamin D-3 with K-2, a company in business since 1932, which is carried at health food stores. “Vitamin D is ideally taken with vitamin K to be sure that the increase level of calcium that is being absorbed is directed to your bones and not your arteries,” she said.

Stephanie Miranda, who is a certified functional diagnostic nutrition practitioner (FDN) in Prescott, says the best way to find your dosage is to get your vitamin D tested. “You want to know your blood levels. There is an optimal level and there is a below range, deficient level. You wouldn’t want to take 10,000 international units (iu) for very long before being tested.”

Dr. Christina Kovalik, also known as The Vitality Doctor, is a naturopathic physician and acupuncturist who has an office in Scottsdale and opened a second office in Flagstaff in 2020. She agrees that testing vitamin D levels is essential.

“It is important to test the serum levels,” Kovalik said. “I look at optimization for the most benefit on hormones, anticancer benefits, immune system, reproductive benefits and mood/cognition. Optimal serum levels are not what are considered within the normal range by some physicians. I target serum levels at least 60-100.”

Taking sun baths is important too, she advises, about 20 to 30 minutes per day, “with the most skin exposed as possible can benefit, but is a challenge here in Flagstaff,” Kovalik noted. “Even people who work outside may still be deficient. People also wear more sunscreen to block the body’s ability to make vitamin D.”

Unfortunately, deficiency in vitamin D is commonplace. Corinne Sadecki-Lund is a nurse practitioner working with Dr. Whitney James at James-Marco Health in Prescott. With more than 27 years’ experience as an ER nurse, she came to Prescott from Chicago about a year ago and was surprised what she discovered.

“When I see patients for their annual labs, I check vitamin D and vitamin B12 levels,” she said. “Interestingly, when I came here, I saw a lot of patients when their labs were drawn, were vitamin D deficient. I was shocked. I looked it up and found that across the United States, when people get their labs drawn, 42% of the time, they are vitamin D deficient.”

She had thought this would be less of a problem in a sun-rich state like Arizona. “People are worried about how much sun they get because of skin cancer,” Sadecki-Lund said. “They say the sun should provide half the amount you need, but unless you’re golfing or out in the sun a lot, you’re not going to get the vitamin D your body requires. I do tell them to go get their sunshine, but just be mindful of their time.”

It is also important not to take more vitamin D that is recommended by the packaging or by a health care provider. Vitamin D can build up in the body and lead to toxicity, with a variety of symptoms such as fatigue, confusion, dehydration and pain. Sadecki-Lund said there are other problems that arise from too much vitamin D in the body.

“Too much vitamin D can cause stomachaches, kidney stones, dizziness and gastrointestinal issues like constipation,” Sadecki-Lund explained. “More than taking the standard dose of 2,000 to 5,000 iu per day may be too much. You can get toxicity. People think the more you take the better it is, but that’s not necessarily true.”

Diet is also important and should include foods that provide the highest amounts of naturally occurring vitamin D. Because it is challenging to get enough vitamin D from food sources, manufacturers have been fortifying food with vitamin D since the 1930s. Readily available vitamin-D-fortified foods include cow’s milk, soymilk, cereal and orange juice.

Kovalik recommends eating vitamin D-rich foods, especially more servings of fatty fish such as salmon, mackerel and sardines. Also high in natural vitamin D are oysters, eggs, liver and shitake mushrooms.

“Eat wild-caught, not farm-raised fish,” she said. “Some food items are fortified in Vitamin D but is usually not enough to be significant.”

Sadecki-Lund said she was pleased when she found out how vitamin D-rich egg yolks are, as she loves them.

Another controversial question is how much vitamin D you should get from foods and supplements. “We have a pretty extensive section on vitamin D, everywhere from 400 to 10,000 international units (iu),” said Miranda, who has also worked in the supplement section of Sprouts Farmers Market in Prescott for four years. In addition to capsules and tablets, Sprouts also sells vitamin D in dropper, spray and sublingual forms.

“Some people have a hard time absorbing Vitamin D, so adding A and K can help with absorption,” said Kovalik. “It is a fat-soluble vitamin, so eating it with a meal that contains fat can also help with absorption.”

Research has shown that getting enough sun exposure is particularly difficult in regions north of the 37th parallel, where the sun is lower and UVB rays are weaker, such as Oregon, Washington, Idaho, Utah and central and northern areas of Nevada and California.

“Even in Arizona, the angle of the sun doesn’t give us enough vitamin D,” Miranda said. “Most of our vitamin D receptors are in our torso; that can be challenging when you’re walking around.”

The good news, according to the medical experts, is that as the summer sun returns, we can consider adjusting our strategy for getting adequate levels of the “sunshine vitamin” by finally taking that sunny walk in the garden. QCBN

By Betsey Bruner, QCBN

Photo by Betsey Bruner: Vitamin D can be found in supermarkets like Sprouts Farmers Market that offer a wide selection of vitamins and supplements.