1. Dry skin
Sure, dry skin, especially in colder weather, may not be all that uncommon. But if your skin is feeling flakier than usual, a lack of healthy omega-3 fatty acids in your diet may be to blame. Omega-3s help nourish your skin’s lipid barrier, the layer of oils that keeps harmful germs and toxins out and essential moisture in. Without a sufficient amount of omega-3s your skin loses moisture, which can lead to an unpleasantly scaly texture. You may even notice more wrinkles and visible aging due to skin dehydration. Avoid developing an omega-3 fatty acid deficiency by eating a diet rich in essential fatty acids.
2. Pale skin
An unhealthily pale complexion may signal that something is going on with your iron levels. Iron deficiency causes red blood cells to be smaller, fewer and filled with less hemoglobin, which makes them less red, says Kaleigh McMordie, a registered dietitian nutritionist based in Texas. The result is paler skin that’s most noticeable on the linings of your eyelids and your mucus membranes (for instance, the tissues inside your mouth). Iron deficiencies need to be checked out by a doctor, but you can up your iron intake with lentils, beef, spinach and iron-fortified cereals.
3. Cracked and dry lips
Need the occasional swipe of lip balm? Not an issue. But seriously cracked and sore lips might indicate you have a riboflavin deficiency. A riboflavin deficiency can cause cracking at the corners of the mouth and dryness around the outside of the lips. It will usually be accompanied by a swollen, dark-red tongue and swollen mouth. Riboflavin deficiency can turn more serious if it’s left untreated. It can sometimes cause nerve damage that can lead to tingling in your fingers or toes. Have these symptoms checked out as soon as possible to address the deficiency in its earliest stages. And, in the meantime, include more riboflavin in your diet by consuming almonds, salmon, broccoli, cheddar cheese and eggs.
While no single food can unilaterally cause acne (old rumors about chocolate and pizza causing breakouts have been thoroughly debunked), some nutrient deficiencies might make breakouts more frequent or more severe.If you’re lacking omega-3s, you might notice more inflammation overall, which can manifest as acne. Omega-3s’ role in maintaining your skin’s lipid barrier comes into play too. Your skin’s natural oils have antimicrobial properties, and an omega-3 fatty acid deficiency that disrupts your lipid barrier may let acne-causing bacteria in.
5. Wounds that won't heal
Cuts and scrapes don’t generally heal overnight, but missing nutrients in your diet can mean that even the tiniest razor cut seems to stick around forever. Slow wound healing might signal that you need more protein in your diet. Protein is essential for building and repairing tissue. Aim for 20 to 30 grams of protein at each meal. Drink a glass of milk with dinner, add beans to your salads or top your apples with peanut butter for some extra protein. You should also eat plenty of fruits and veggies for vitamin C because low levels of this nutrient can slow healing (and, in severe cases, even reopen old wounds). Strawberries, red peppers and grapefruit are some of the best sources.
6. Bleeding gums
If your gums start bleeding for no apparent reason, you might be dealing with a vitamin K deficiency. Vitamin K is best known for its role in helping blood clot, or coagulate. It sets off a cascade that activates pro-clotting factors in your blood, which help you stop bleeding after a cut and also prevent spontaneous bleeding from delicate tissues like your gums. Vitamin K deficiency is generally pretty rare, so check with your doctor and dentist to investigate the cause of your bleeding.
7. Brittle nails
If you’re constantly dealing with painful hangnails and nail breaks, your diet might be low in biotin. Biotin nourishes your nails’ growth plates. Disrupting your growth plates, not surprisingly, leads to irregular growth, instead of the thick, strong nails you’d like. Getting more biotin helps your nails grow stronger — one study even found that biotin supplementation boosted nail thickness by as much as 25 percent. Eat eggs, nuts and whole grains to boost your intake of this nutrient and give yourself tough-as-nails nails.
8. Discolored nails
While weak nails are annoying, other nutrient deficiencies can make your nails look a little, well, weird. Low iron levels can lead to whitened or ridged nails, explains Bucher, and can even cause concave and spoon-like nails. A biotin deficiency ups your risk of fungal infections that can cause ridging and discoloration, while a vitamin B-12 deficiency can make your nails take on a brownish hue. See a doctor if you’re noticing abnormalities in your nails.
9. Thin and weak hair
How well you eat ends up reflected in the health of your hair. While losing some strands is normal (we lose between 50 and 100 hairs daily), noticeable thinning of your hair may not be. Protein and vitamin C deficiencies can cause thinning or brittle hair and hair that falls out easily. That’s because vitamin C helps you make collagen — one of the building blocks of healthy hair and a strong hair follicle — while protein supplies amino acids for collagen (and other protein) synthesis. Biotin might also play a role: A recent study found that nearly four in 10 women who reported suffering hair loss had a biotin deficiency.
10. Premature gray hairs
On top of changing your hair texture, certain nutrient deficiencies can make you go gray. Copper helps you create melanin, one of the pigments that gives your hair its color. Low copper levels — or an underlying medical issue that prevents you from metabolizing copper properly — can turn your hair gray, says McMordie. Low vitamin D levels might also trigger premature graying: A recent study found that low vitamin D levels were associated with graying that starts as early as childhood. Snack on almonds or hazelnuts for copper and drink fortified dairy products (or fortified milk alternatives) for vitamin D.