If Sun Makes You Happier, Think about Your Vitamin D Level

Sun-bathers know how relaxing it can be to lie around drinking up light. Our bodies make Vitamin D from sunlight, which is linked to mood.

Some people never go outside without a sunscreen or keep themselves entirely covered up. Actually, your body produces the first step in making Vitamin D well before your skin turns pink. There’s no need to get tanned or burned.To get your daily dose of sunlight, go outside with at least your face exposed for about 10 to 20 minutes during mid-day. People with darker skin need the most light and may need more time.

Although you can be deficient in Vitamin D at any age, your risk increases as the years go by, and your body becomes less efficient at making Vitamin D and using it. Food alone won’t fill a deficiency: Milk, oily fish and egg yolks all contain Vitamin D, but not enough. It could take dozens of glasses of milk to match the Vitamin D generated by ten minutes of summer sun on bare skin.

There's plenty of evidence that lack of sunlight can drag your mood down. People who live in northern climates are more likely to seek out information about depression online during the winter, one study found. Low blood levels of vitamin D are linked to more signs of depression. In other research, people who attempted suicide had much lower vitamin D levels than other depressed people who weren’t suicidal or a group of healthy controls. Vitamin D lowers one kind of inflammation, which has been linked to suicide.

Many parts of the brain, including those involved with depression, contain receptors for Vitamin D. It may increase the available serotonin, the way the SSRIs do.

But the blues have many causes; a Vitamin D problem may be one. The research is still unclear on whether exposing your skin to the sun, sitting under a sunlamp, or taking a vitamin D supplement will reliably help prevent or ease low mood. However, a supplement (don’t take more than 10,000 IU a day) won’t hurt you so you can try it and see whether Vitamin D is a key favor for you.

A simple blood test will help your doctor decide if you need more Vitamin D. Doctors like to see between 30 and 60 nanograms per milliliter of “25- hydroxyvitamin D.” This chemical travels throughout your body, turning into “activated vitamin D,” which helps your cells communicate and manages the calcium in your blood, bones and gut.

Even if your mood is bright, meeting your Vitamin D needs is important for overall health. Vitamin D is associated most closely with strong bones and a healthy heart. In a study of nearly 1,500 Finns researchers found that people with low Vitamin D levels also had higher total and low-density lipoprotein “LDL” cholesterol and triglyceride levels, and higher systolic and diastolic blood pressure. Around the world, heart problems are less common in places where people get more sunlight. Low levels of Vitamin D in dark climates also may contribute to weak muscles, infections, type 2 diabetes and dementia. Too little light may play a role in autoimmune diseases like multiple sclerosis as well.

Your doctor might recommend a supplement or give you an injection for an immediate boost. If you decide to get a sunlamp, choose one that emits short-wavelength UVB light, which triggers Vitamin D production. Manufacturer Sperti claims that its Vitamin D Lamp ($425) is the only one recognized by the Food and Drug Administration for this function. Don’t go to a tanning salon or buy a tanning lamp: your goal isn’t to damage your skin, but to feed your body.

A version of this story appears on Your Care Everywhere.