Your nails are brittle
When your body is running low on the mineral iron, parts of the body become weak and pale. This may express itself as brittle fingernails—or toenails—or pale inner eyelids. Women with heavy menstrual bleeding are at a greater risk for iron deficiency, as are vegetarian women—although men are more likely to have excess iron intake, per a report by the U.S. Centers for Disease Control and Prevention (CDC). The fix: Premenopausal women need 18 milligrams (mg) a day, and men and postmenopausal women require 8 mg. Your body best absorbs animal-based iron, the type found in meat, poultry, and seafood. Pair vegetarian sources of iron, such as spinach or chickpeas, with citrus or other vitamin-C-containing foods to increase absorption.
Your blood pressure is too high
You may be low on vitamin D. Although only 3 percent of non-Hispanic whites are deficient, 31 percent of non-Hispanic blacks and 12 percent of Mexican-Americans don’t get enough, according to the CDC study. Preliminary research links higher intake of this fat-soluble vitamin with lower blood pressure—and people who get enough aren't as likely to develop hypertension. The fix: Adults need 600 international units (IU) of vitamin D daily. This is one nutrient that’s difficult to get from food, as few options contain significant amounts. But here are a few that do: swordfish, salmon, fortified milk and orange juice, and mushrooms grown in sunlight or UV light, such as those produced by Monterey Mushrooms. Supplementation in postmenopausal women and older men may be beneficial; choose the D3 version, the active form of the vitamin. These 8 foods may help reduce blood pressure.
Your blood pressure is too low
This is one of many possible symptoms of vitamin B12 deficiency—a lack of this water-soluble vitamin can affect the neurological system, preventing the body from naturally bringing blood pressure back up. Others symptoms of vitamin B12 deficiency include unsteady gait, muscle weakness, and lack of bladder control. The fix: Adults need 2.4 micrograms (mcg) daily. Excellent food sources include clams, trout, salmon, and fortified cereals; beef, milk, and eggs are good sources. If you go the supplement route, sublingual (under the tongue) may be a better choice for older adults, who sometimes have a hard time absorbing the vitamin through food or oral supplements, due to lower levels of stomach acidity.
Your leg muscles are cramping
Your body needs the electrolyte potassium to build muscle and protein. A dip in levels of the mineral can cause muscle cramping, often appearing in the calf area. Potassium deficiency is rarely caused by low dietary intake—excessive sweating, diarrhea, vomiting, and loss of fluid are the more likely culprits. The fix: You need 4,700 mg daily, and food sources include sweet potato, banana, avocado, and coconut water.
You’re feeling tired
While scurvy, or vitamin C deficiency, may make you think of pre-18th-century sailors, inadequate intake of the immunity-supporting nutrient is seen in specific groups, including smokers and people exposed to secondhand smoke. In fact, smokers have a more than three-fold greater risk of vitamin C deficiency, per research in the American Journal of Clinical Nutrition. Feeling tired all the time and irritability are symptoms that you may have dipping vitamin C levels. The fix: Women need 75 mg daily, and men require 90 mg—while smokers need an extra 35 mg daily. Citrus, cantaloupe, kiwi, pineapple, tomatoes, spinach, bell peppers, and broccoli are all excellent sources.
Your thyroid hormone production has dipped
You would only know this for sure via lab work, and low levels might be linked with decreased intake of the mineral iodine. Although rare in the U.S., very low iodine levels may reduce production of the thyroid hormone, which could lead to hypothyroidism. Low iodine intake is especially worrisome for pregnant women—it can cause miscarriage and many other problems. Women of childbearing age had iodine levels just above iodine insufficiency, on average, in the CDC report. These subtle signs may indicate a thyroid problem. The fix: Most adults need 150 mcg daily, while pregnant women need more (220 mcg). If you cook with salt or add any to your food, opt for iodized salt over sea salt and other varieties. Seafood and dairy also contain iodine.
You’ve had several recent fractures
When you’re deficient in the mineral calcium, you’re at risk for osteopenia, a condition that causes low bone mass and heightens risk of osteoporosis and bone breaks. Bones reach max strength at around age 30—at which point they start to slowly lose calcium. This is why it’s important to take in proper amounts of calcium, alongside weight-bearing activity such as walking and aerobics. The fix: Men and premenopausal women need 1,000 mg daily, and postmenopausal women require 1,200 mg. The best food sources of calcium include dairy (yogurt, milk, and cheese), some leafy greens (collard greens, turnip greens, and kale), tofu, edamame, and fortified juice. If you choose to take a supplement, divide into two doses and pair each with a meal.
You have cracking at the corners of your mouth
Although not super common, a vitamin B6 deficiency can reveal itself through skin conditions—also including scaling on the lips or an inflamed tongue—as well as through depression or confusion. The body’s small supply of the water-soluble vitamin typically lasts several weeks, so deficiency appears once the body is fairly depleted. Some types of oral birth control may affect vitamin B6 status, as can certain corticosteroids and anticonvulsants. The fix: People up to age 50 need 1.3 mg daily, while older women need 1.5 mg and older men require 1.7 mg. Dietary sources include chickpeas, tuna, salmon, fortified cereal, bananas, and marinara sauce—although deficiencies are typically treated by a doctor with a daily supplement of 50 to 100 mg.