Vitamin deficiency: causes, symptoms and prevention

Potassium is a mineral your body needs to work well. It’s an electrolyte that helps your muscles, nerves and heart do their jobs.⁴

Hypokalemia means your potassium level is low. It’s common to have mild low potassium levels show up on routine blood tests. Many people may not know they have it because symptoms can be mild or easy to miss.⁵

Signs are more likely when potassium is very low or drops quickly. You may notice muscle aches, heart palpitations, tingling or numbness, tiredness or constipation. When potassium levels are very low, your blood pressure may go up.⁴

If you have low potassium levels, your doctor may suggest eating foods with high potassium or taking a supplement. Most adults need around 4,700 mg of potassium per day. Common potassium-rich foods include:^{2, 4}

• Avocados
• Bananas
• Beans and lentils
• Citrus fruits
• Green leafy vegetables
• Fish
• Mushrooms
• Potatoes
• Raisins and dates
• Tomatoes
• Yogurt and milk

Vitamin D helps keep your bones strong and healthy. It also supports your muscles, nerves and immune system.⁶

If your vitamin D level is low, you may have bone or muscle pain. You may also feel tired, lose hair, have mood changes or have wounds that heal slowly. Other signs may include muscle twitches, blood sugar problems, bones that break more easily or trouble with memory or focus. These signs can also happen for other reasons. Some people with low vitamin D do not have any symptoms.⁶

When your vitamin D level is too low, it may affect your health in different ways. Low vitamin D has been linked to diabetes, heart disease, dementia, depression and osteoporosis.⁶

To raise your levels of vitamin D, you may need more sunlight, to eat certain foods or take a supplement. Most adults need at least 600 IU of vitamin D per day. Foods that are good sources of vitamin D include: ^{2, 6}

• Egg yolks
• Fatty fish (like salmon and tuna)
• Fortified milk, breakfast cereals and orange juice
• Mushrooms

Calcium helps keep your bones and teeth strong. It also helps keep your heartbeat steady.² 

Most of the calcium in your body is stored in your bones and teeth. If your body doesn't get enough calcium, it may pull calcium from your bones. This can happen without you noticing.²

Some people may be more likely to have low calcium levels. This includes people who have gone through menopause, avoid dairy foods, have low thyroid hormone levels or take certain medicines.²

Low calcium may not cause symptoms at first. If it stays low for a long time, you may have tingling in your hands or feet. You may also have muscle spasms, feel more tired than usual, have mood changes or notice coarse hair, brittle nails or dry skin.²

Over time, low calcium may also weaken your bones and raise the risk of osteoporosis.²

Most adults need at least 1,000 mg of calcium each day. Adults over 50 may need about 1,500 mg a day. You can get calcium from foods such as:²

• Calcium-fortified plant-based beverages, like soy milk
• Cooked spinach, turnip greens or kale
• Dairy products, including milk, yogurt, cheese and cottage cheese 
• Fish without the bones removed

Iron helps your body make red blood cells. These cells carry oxygen to all parts of your body. Iron also helps support hormones and brain health.²

Iron deficiency is common, and many people may not know they have it. It may not be found until iron levels are low enough to cause iron-deficiency anemia.²

Iron deficiency can be hard to spot because the signs may feel like everyday tiredness or stress. You may feel weak, have restless legs, notice hair loss, get headaches, have trouble focusing or get sick more often.²

Some people may be more likely to have low iron. This includes breastfed babies between 7 and 12 months old, and people who are pregnant or who menstruate. Low iron can also happen to people who have digestive issues, cancer, heart failure or who donate blood.²

The amount of iron you need each day can depend on your age, sex and whether you are menstruating, pregnant or breastfeeding. Here is a simple guide:²

• Men: 8 mg 
• Women: 18 mg 
• Pregnant women: 27 mg
• Breastfeeding women: 10 mg
• Adults age 51 and older: 8 mg

The best sources of iron come from meat and seafood. Other food sources of iron include:²

• Boiled lentils
• Boiled spinach
• Fortified infant cereals 
• Kidney beans
• Tofu
• Whole-grain breakfast cereals