Like bears fattening up before hibernating, many people experience food cravings and fatigue as winter approaches. Some people also report feeling unusually blue when the temperature drops and nighttime comes earlier. Interestingly, certain nutrients may help ward off winter blues.

Doctors still have the best treatments for seasonal depression, which keeps a person feeling down not just for a day or two, but for days on end. The treatments include medicine, counseling and therapy with special lights.

Along with that, outdoor walks and getting enough vitamin D and certain fish may help people to pull through the dark winter, whether their seasonal mood shift becomes a severe case of depression or not.

Feeling SAD

Seasonal Affective Disorder, SAD for short, generally makes people feel down or lethargic in fall and winter, and better during spring and summer (though some people do have the opposite pattern).

Scientists aren’t sure exactly what causes SAD, but research shows that shorter days and less sunshine do affect brain chemicals.

A Swiss study of people with seasonal depression confirmed that these people crave carbohydrate-rich foods during fall and winter, and their blood sugar rises faster then, too.

We know that eating carbohydrates can raise levels of serotonin, a natural mood-booster. So people may be self-medicating their sad feelings with cookies and other sweets.

Instead of cookies, studies show that mild exercise, sunshine, vitamin D and fatty fish may help people with SAD.

Russian scientists found that treatment with special lights or stationary cycling an hour daily improved moods and helped people lose weight gained due to seasonal depression.

The Levity (Light, Exercise and Vitamin Intervention Therapy) trial in Seattle suggested that brisk walks and vitamins can ease mild to moderate depression. Specifically, participants walked outdoors in the sunshine for 20 minutes five days a week. They also took a vitamin supplement equivalent to a vitamin B complex plus 200 micrograms of selenium and 400 units of vitamin D.

The happy vitamin

Vitamin D is being studied all by itself as a treatment for SAD. We know people’s vitamin D levels fall in autumn and winter. That’s because we get most vitamin D from sunshine — UV light hits the skin and triggers a series of chemical reactions to create vitamin D.

The less sun exposure, the less vitamin D people make. Thus, people who work indoors, live in the northern half of the United States, wear sunscreen or have darker skin — which is a kind of natural sunscreen — all have lower levels of vitamin D. So do the elderly and people with certain digestive problems.

Researchers currently are arguing over how much vitamin D is enough. Depending on what numbers are used, one-third to two-thirds of Americans have low blood levels of vitamin D.

Vitamin D is best known for its link to healthy bones, muscle strength and the immune system. Recently, researchers in St. Louis and the United Kingdom linked low levels of vitamin D to depressed moods.

The government recommends 400 units of vitamin D daily, but many experts say that is not enough. Taking 800 units of vitamin D daily did not prevent seasonal depression in women over the age of 70, according to a study in New York. However, a Maryland study showed that a single very high dose, 100,000 units of vitamin D, eased seasonal depression.

This is such a high dose, though, that it would be dangerous to take unless monitored by a physician. The tolerable upper limit for vitamin D is 2,000 units a day, according to the federal government.

It’s hard to get much vitamin D from foods — a cup of milk has only about 100 units.

Eat more fish

Eating 3 ounces of some fish can provide 200 to 500 units of vitamin D and also omega-3 fats, which are being studied in their own right as mood boosters.

Fatty fish such as wild salmon, mackerel, herring, tuna and sardines may be especially helpful for seasonal depression.

Seasonal depression is rare in Iceland, despite the fact that the country is far north and has long winters; the disorder is very low in Japan as well, according to the American Journal of Psychiatry. The average Icelander eats 225 pounds a fish a year, and the average Japanese eats 147 pounds, compared with 48 pounds for an American.

For the winter blues

The symptoms of seasonal depression are like those of depression, which can strike any time of year. They include hopelessness, anxiety, loss of interest in usually pleasurable activities and a change in appetite. The difference is that, with SAD, these symptoms occur only seasonally.

If you have seasonal depression, see your doctor immediately. Depression is a serious illness that needs to be treated, not only because it feels bad, but also because it can lead to suicide. It’s also important to check with your doctor before taking any supplements.

Talk a daily, 20-minute walk outdoors. And take a standard multivitamin supplement, not a megavitamin — a standard multivitamin has about 400 units of vitamin D.

If you want more vitamin D, buy separate vitamin pills of vitamin D-3, also known as cholecalciferol. It’s more potent than vitamin D-2, or ergocalciferol. Don’t take more than 2,000 units total per day.

Finally, eat fatty fish at least twice a week, or consider fish-oil supplements.

— From Fredricksburg.com