Our bodies need nutrients to run at their best. There are macronutrients—carbohydrates, fats and protein—that we need in large amounts because they provide energy, and micronutrients—vitamins and minerals.
As the name implies, we need these micronutrients in smaller amounts, but that doesn’t mean they’re not crucial. Vitamins and minerals play key roles in keeping every part of the body working well. The health of your brain, blood, bones, cells, organs, hormones and immune system all depend on them.
“With a well-rounded diet, you can get sufficient amounts of these vitamins and minerals,” says UNC Health registered dietitian Natalie Newell. “But if you’re not eating very well, or if you’re sticking to the same thing day every day, you might not get the vitamins or minerals you need.”
When we’re deficient in these micronutrients, we don’t feel our best. We asked Newell about common nutrient deficiencies and which foods can fix them.
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Vitamin D
Vitamin D is important for our bone health, but it’s an incredibly common vitamin deficiency. Without it, you may feel fatigued, weak and generally unwell.
“Most people aren’t consuming vitamin D on a regular basis because it’s not very common in food,” Newell says. Vitamin D is found in fatty fish such as salmon, mackerel, tuna and sardines, as well as egg yolks, liver and mushrooms. It’s also fortified, or added, to some cereals, juices, milks and yogurts.
Sunlight on your skin prompts your body to make and use vitamin D, but sunscreen blocks these rays. Sunscreen should be used the majority of the time to protect your skin from cancer, but talk to your healthcare provider about your specific situation. You may be able to spend 10 to 15 minutes outside a few times per week without sunscreen for the vitamin D benefits.
Older adults, people with darker skin and people with obesity are at higher risk for a vitamin D deficiency. Celiac disease, cystic fibrosis, Crohn’s disease and kidney disease, as well as some medications, can make it difficult for your body to absorb vitamin D.
Your doctor may recommend a supplement—more on these later—but if not, check with them before you start taking one.
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Calcium
Like vitamin D, calcium is important for bone health; in fact, vitamin D helps your body absorb the calcium it needs from food, so deficiencies in D might lead to deficiencies in calcium. But even with enough vitamin D, many people don’t get enough calcium. That can have a huge impact on your bone density, or the strength and durability of your bones, as you age.
“We lose bone density as we age, so it’s really important to maintain what you have so you can avoid fractures,” Newell says.
Calcium also affects the functioning of muscles, blood flow and nerve signals from the brain to the rest of the body. Fatigue or muscle cramps could indicate a calcium deficiency.
Dairy products, including milk, yogurt and cheese, are good sources of calcium, as are collard greens, kale, broccoli, figs, oranges, sardines and salmon. Some plant-based milks, juices and tofu are fortified with calcium.
It’s important to space out your consumption of calcium.
“The body can absorb only 500 milligrams of calcium at a time, so don’t take a multivitamin or a supplement at breakfast if that’s when you consume dairy products,” Newell says.
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Iron
Iron is essential for your body’s ability to make hemoglobin, a protein in red blood cells. Red blood cells transport oxygen throughout your body, so if you don’t have enough iron, you have fewer red blood cells able to complete their task. When you can’t get enough oxygen throughout your body, you have iron-deficiency anemia, which causes symptoms such as fatigue, shortness of breath and pale skin.
Fortunately, many foods have iron.
“Red meat, poultry and fish have significant iron,” Newell says. “Lentils, beans, leafy greens, broccoli, seeds and nuts have iron as well.”
Some cereals and breads are fortified with iron.
Women are more at risk for iron deficiency due to menstruation but consider your diet and talk to your doctor before adding a supplement, as iron supplements are known to cause constipation.
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Vitamin B12
Anemia can be caused by a deficiency in iron, but it can also be caused by a deficiency in vitamin B12. That’s because this vitamin also helps with red blood cell production; beyond that, it helps nerve function, so a deficiency can cause numbness or tingling sensations, weakness, memory loss and depression.
Vitamin B12 is found only in animal products—meat, fish, dairy and eggs—so if you’re a vegan, you may not be getting enough. Some vegan and vegetarian products, such as plant-based milks, cereals, beans and nutritional yeast are fortified with B12.
What to Do If You’re Concerned About a Vitamin or Mineral Deficiency
These deficiencies have common symptoms—fatigue, weakness and feeling unwell—but you’re not going to be able to tell on your own which specific deficiency you have.
“Your diet could be the reason you feel fatigued, but don’t make an assumption that it’s iron or B12 and start adding supplements yourself,” Newell says. “First, get a blood panel during your physical.”
That blood work will pinpoint specific deficiencies, and your healthcare provider or a registered dietitian can consider those deficiencies in the context of your specific situation. If you’re pregnant or hoping to become pregnant, for example, you’ll have different nutritional needs. If you’re taking a weight loss medication or you’re in your 60s or older, you may be eating less and need expert advice on how to get the nutrients you need in smaller meals.
Next, consider your diet. Vitamins and minerals tend to be absorbed better from food sources compared to supplements, pills or powders with individual nutrients or combinations of them.
“Start to pay attention to what you’re eating, and keep a food journal to track,” Newell says. “What we think we’re eating and what we’re actually eating is usually not the same.”
Newell recommends tracking a few different days over a few different weeks—you may always be meal-prepped and ready to go with nutritious meals on Monday and Tuesday but scrounging by the weekend and making less healthy choices.
Remember that the foods with the most nutrients can be found on the perimeter of the grocery store.
“Stay out of the middle of the grocery store, where the ultraprocessed foods are,” Newell says. “Aim for a colorful plate with protein and plenty of fruits and vegetables.”
If you’ve adjusted your diet and still have vitamin deficiencies, talk to your provider or a dietitian about whether you need a supplement.
“Most people can take a general multivitamin, but additional supplementation should be really individual,” Newell says. “Adjust your diet to address a deficiency first and then consult with a doctor or dietitian for the best plan for your needs.”
Questions about nutrition? Talk to your doctor or find one near you.