When the frigid temperatures set in, you’ll probably be ready to pull out your floor-length hoodie or fluffy scarf to stay warm. Or maybe you’re ready to stay indoors and avoid winter weather altogether.
However, dressing in layers and spending less time outdoors will limit your sun exposure and reduce the levels of vitamin D that your skin produces when it absorbs UV rays from the sun.
Approximately 40% of Americans are deficient in vitamin D, and vitamin D deficiency is especially prevalent in northern regions where winters are the harshest.
So here’s how to make sure you’re getting enough vitamin D this winter.
Why is vitamin D important?
Vitamin D helps the body absorb calcium, which is necessary for bone health. Vitamin D is also essential for nerve function and maintaining a healthy immune system.
So how can you tell if you’re getting enough vitamin D? Unfortunately, it can be difficult to recognize because many people don’t experience any noticeable symptoms.
“If you’re deficient in vitamin D, you probably won’t feel it,” says Andrea N. Giancoli, MPH, RD. “The best thing to do is to have regular blood tests to make sure you’re within a healthy range.”
This is important because vitamin D deficiency can have negative health effects. It has been linked to seasonal affective disorder (SAD), and research suggests it may also be linked to chronic conditions such as cardiovascular disease.
And while vitamin D deficiency is associated with increased mortality, researchers are still working to establish a causal relationship between the two.
Extremely low vitamin D levels can also affect bone density. “Vitamin D helps your body absorb calcium, and works with calcium to keep your bones strong and healthy,” says Rachel Daniels, RD, MS, RD, at Virtual Health Partners. “Severe vitamin D deficiency can lead to softer bones and decreased bone density, which can lead to pain, weakness, and increased risk of injury.”
How can I get vitamin D?
There are three ways to get vitamin D: from the sun, through diet, and through supplements.
1. Nikko
The easiest way to get vitamin D is through sunlight, but how long do you need to be in the sun to synthesize enough vitamin D? The ideal range depends on a variety of factors. It will take 5 to 30 minutes.
Time of day (the sun is strongest at noon) Season Location Altitude Age Skin pigmentation (darker skin tone requires more time in the sun to produce enough vitamin D)
There’s one catch. Sunscreen blocks the absorption of ultraviolet light, which can affect vitamin D production.
“For vitamin D to be synthesized, UVB rays need to hit the skin,” Giancoli says. “Wearing sunscreen all the time prevents the absorption of UVB rays and inhibits the potential for vitamin D synthesis.”
Of course, you know how important it is to wear sunscreen every day, even in the winter, as exposure to the sun’s UV rays increases your risk of skin cancer. So how do you balance getting enough sunlight to synthesize vitamin D without damaging your skin?
“You want to get enough sunlight to synthesize vitamin D, but you don’t want to get so much sun that it increases your risk of sunburn and skin cancer,” Giancoli says. Her rule of thumb is to always apply sunscreen before you notice any changes in skin color, such as sunburns or burns.
2. Food
Although exposure to sunlight is the best and most efficient way for your body to get vitamin D, you can also get vitamin D from certain foods. The following foods are considered good sources:
Because vitamin D is not found naturally in many foods, you may have noticed that milk, yogurt, orange juice, and cereals are often fortified with vitamin D.
3. Supplements
A balanced diet can help add more vitamin D to your diet, but “at this time of year, you may not reach the recommended dietary intake of 600 international units (IU) per day without supplements.” “Yes,” Daniels said.
If you don’t get much sunlight during this time, you may want to consider taking a vitamin D supplement, but check with your doctor before doing so.
“When it comes to supplements, more isn’t always better,” Daniels says. Your doctor will check your current vitamin D status with a blood test and recommend appropriate supplements and dosages.
Can light therapy increase vitamin D levels?
Light therapy is a common treatment for seasonal affective disorder. However, most light therapy boxes (sometimes called “happy lights”) are designed to limit UV exposure to prevent skin damage. This means that your vitamin D levels will not increase. However, one study found that ultraviolet light from artificial sun lamps, such as the types used in tanning beds, may help improve vitamin D status.
Still, the best and most efficient way to boost your vitamin D levels is through natural sunlight exposure. So, while fortified foods, fatty fish and artificial solar lamps may help, your best bet is to brave the cold and soak up some rays for a few minutes each day. On those gloomy days when the sun is nowhere to be seen, consider taking a supplement.
