You already know a lack of iron can drag you down.

But experts say numerous vitamin and mineral deficiencies can contribute to fatigue. If left unchecked, the same deficiencies that make it hard to keep your head up can lead to long-term health consequences — from brittle bones to impaired brain function.

“Fatigue can be like an early warning sign of potentially more severe problems down the road if you don’t recognize and treat the problem causing the fatigue,” says Dr. Anthony Komaroff, a professor of medicine at Harvard Medical School and a senior physician at Brigham and Women’s Hospital in Boston. “You need to explore all possible explanations for your fatigue.” That goes for ongoing feelings of exhaustion to concerns about muscle fatigue being more pronounced or prolonged than might be expected from physical activity.

Some of the most common causes of fatigue — and easiest things to test for — involve deficiencies in three minerals and two vitamins, Komaroff says. After iron comes lack of magnesium, potassium, vitamin B12 and folic acid. “All of them can be corrected by giving supplements of the missing minerals or the missing vitamins,” he says, or through dietary changes.

“More serious problems than just the fatigue can develop from these vitamin and mineral deficiencies,” Komaroff says. “For example, vitamin B12 deficiency, if it goes on long enough, undiagnosed and untreated, can lead to permanent damage of the brain and the spinal cord that can affect people’s ability to move, walk and think clearly.”

Even the mundane can become imperiling — such as untreated anemia from iron deficiency. “Iron is needed to build hemoglobin, which is what is inside the red blood cell,” Komaroff explains. “It carries oxygen, which is a critical source of energy to every cell in the body.”

Anemia often occurs in women as a result of blood loss due to menstruation, though it can affect women of any age as well as men. In mild cases, it can escape detection. But as iron deficiency becomes more severe — and if left uncorrected — symptoms can escalate to include severe fatigue, headache, chest pain and increased heart rate. Besides iron, vitamin B12 or a folic acid deficiency can also lead to anemia.

One factor that may be largely to blame for vitamin deficiencies is a national obsession with restrictive diets, according to Jessica Crandall, a Denver-based registered dietitian nutritionist and a spokeswoman for the Academy of Nutrition and Dietetics. “Most Americans are engaging in some kind of fad diet throughout their life, and when they do that, they are cutting out food groups, [which] can cause repercussions, such as nutrient deficiencies,” Crandall says.

A big sandwich might make you sluggish; but, she says, cutting out carbohydrates — the centerpiece of several popular diets — has left many feeling like they’re forever out to lunch.

“I’ve seen a serious rise in people cutting out carbohydrates from their diet, whether it be they’re following an Atkins or South Beach or Paleo-type of diet,” Crandall says. “When you cut carbohydrates out of your diet, you essentially are restricting a lot of the B vitamins as well as essential nutrients to provide your brain’s energy it needs to function.” Low-carb consumption, and resulting deficiencies — including in vitamin B12, which is already not absorbed well by women over age 50 — can cause brain fog or mental fatigue as well as physical exhaustion, she says.

“So we know we need to make sure we’re getting B12, whether that be from fortification, supplementation or our primary source, which would be our food groups,” Crandall says. She recommends eating a variety of foods and consulting a registered dietitian if considering food restrictions to lose weight. That’s in addition to reviewing lab tests with your physician to unearth any potential deficiencies.

Haphazard calorie cutting and meal timing, including skipping meals, can also contribute to vitamin and mineral deficiencies, as well as fatigue, she says. “I always encourage my clients to eat within the first hour of waking up to better kind of fuel their metabolisms and get their brain and body functioning,” Crandall says.

Whether a vitamin or mineral deficiency is contributing to tiredness, experts say it’s always worth exploring the cause from a health and wellness standpoint. There’s no shortage of potential culprits for fatigue from lifestyle issues, such as lack of sleep and not exercising enough, to more insidious causes, including underlying heart disease.

Felicia Stoler, a registered dietitian nutritionist and exercise physiologist in private practice in Red Bank, New Jersey, recommends that those experiencing chronic fatigue see a doctor to rule out medical causes. The type of fatigue matters, too, in pinpointing if or how a vitamin or mineral deficiency may contribute. While iron, for example, might cause an overall feeling of tiredness, a lack of potassium and magnesium can contribute to muscle aches and cause a person to feel sore and weak, Stoler says.

She, too, typically starts with diet to address mineral and vitamin deficiencies that can trigger fatigue, from recommending more meat, fish, fruit — such as cantaloupe, bananas and apricots — plus potatoes, turnips and other veggies to deliver magnesium; to cashews and peanuts, whole-grain products, fish, poultry and eggs to offset a zinc deficiency, which can also cause fatigue.

“I add supplements as needed,” she says, most commonly for vitamin D deficiencies, which can also invite fatigue and hurt bone health in the long term, increasing the risk for osteoporosis.

Stoler says it’s important to heed vitamin and mineral deficiencies, including those that might contribute to fatigue, and to be mindful of the broader implications. “If you think about why we even started looking at adequate intake levels and dietary guideline levels,” she says, “it’s really preventing … illnesses or disease associated with deficiencies.”

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Is a Vitamin or Mineral Deficiency Making You Tired? originally appeared on usnews.com