8 Weird Signs of Nutrient Deficiency in Women (and What They Mean)
Cracked lips, twitchy legs, and a hairbrush that's suddenly full: what your body may be asking for, and what it has to do with your hormones at every age.
Your body has a funny way of asking for what it needs. It doesn't send a memo or schedule a meeting. It cracks the corners of your lips, makes your legs twitch at 11pm, and leaves a small animal's worth of hair in the shower drain.
I pay attention to these odd little signs in my practice, because they're often the earliest clue that a woman is running low on something. They tend to show up long before a lab flags a problem, and long before anyone thinks to ask.
And here's the part I find most interesting, dear reader: the nutrients behind these signs are the same ones your body leans on to make, use, and clear its hormones. So whether you're 28 with brutal PMS or 45 and deep in perimenopause, a quiet deficiency can turn the volume up on everything.
Why the outside shows it first
When nutrients run short, your body triages. The heart, the brain, and the other vital organs get first claim on whatever is available, and the tissues that aren't essential for survival wait at the back of the line.
Skin, hair, nails, and the lining of your mouth are those tissues. They also happen to be some of the fastest-growing cells you have, constantly being replaced, so they need a steady supply of raw materials. That combination (high demand, low priority) is why a shortage often shows up there before it shows up anywhere else.
It's also why I look at a woman's hands, hair, and lips while she's telling me about her fatigue. The outside of the body is a surprisingly honest record of what's been happening inside for the past few months.
Eight signs worth noticing
None of these is dramatic on its own, which is exactly why they get ignored. For each one, I've included what it may point to and what else could be going on, because both matter.
1. Cracks at the corners of your lips. Those sore little splits at the corners of your mouth (the ones that sting when you yawn or eat something salty) are often tied to low B vitamins, especially B2, B6, B12, and folate, as well as low iron or zinc. They can also come from a yeast overgrowth, cold dry weather, or a habit of licking your lips. If they keep coming back no matter how much lip balm you use, that's the clue.
2. Spoon-shaped nails. Healthy nails curve gently downward. Spoon nails do the opposite: they thin out and dip in the middle, sometimes enough to hold a drop of water. This is one of the classic signs of iron deficiency, usually one that has been building for a long time. It can occasionally run in families or follow repeated injury to the nail, but in a menstruating woman, iron goes to the top of my list.
3. Dandruff. A flaky, itchy scalp is sometimes linked to low zinc or low B vitamins (B2, B6, and biotin get the most attention). The more common driver is a yeast that lives on everyone's scalp and tends to flare with stress, cold weather, and certain hair products. I get curious about nutrients when dandruff shows up alongside other signs on this list.
4. Dry, flaky skin. Skin that stays dry and rough despite your best moisturizer can point to low omega-3 fats, vitamin A, or zinc, all of which help maintain the skin's barrier. Other usual suspects include a sluggish thyroid, long hot showers, winter air, and eczema. Falling estrogen dries the skin too, which is why this one is so easy to write off in midlife.
5. Bumps on the backs of your arms. Those small, rough, "chicken skin" bumps on the upper arms and thighs are sometimes associated with low vitamin A or low essential fats. I want to be honest that they're very often simply genetic and harmless. If yours appeared in adulthood, or they come with very dry skin, the nutrient question gets more interesting.
6. Restless legs. That crawling, twitchy, can't-keep-still feeling that arrives the moment you lie down is strongly tied to low iron. Your brain uses iron to make dopamine, and dopamine helps regulate movement. Low magnesium may play a role too. Pregnancy, kidney problems, and some medications (including certain antihistamines and antidepressants) can also set it off.
7. Muscle spasms and cramps. Eyelid twitches, calf cramps at 3am, and feet that seize up in yoga class make me think of magnesium first, then potassium and calcium. These minerals control how muscles contract and release. Dehydration, a hard new workout, and medications like diuretics are common causes that have nothing to do with your diet.
8. Hair falling out. More hair in the brush, in the drain, and on your sweater can point to low iron, zinc, vitamin D, or not enough protein. Shedding also tends to show up about three months after a major stressor like illness, surgery, childbirth, or rapid weight loss, and a struggling thyroid is a frequent cause as well. This is one where I always want labs before guesses.
A quick but important caveat: these are clues, not a diagnosis. Every one of them has other possible causes, and more than one nutrient can sit behind the same symptom.
A few more for the list
Once you start looking, you'll notice others. A sore, smooth, or swollen tongue can go with low B12, folate, or iron. Tingling or numbness in the hands and feet is a reason to have B12 checked promptly. Bleeding gums and easy bruising can point to low vitamin C. And a strong urge to chew ice is one of the stranger and more reliable signs of low iron.
Protein deserves its own moment
We talk about vitamins and minerals constantly, and protein gets treated like a gym topic. But it may be the most overlooked nutrient of all, and your fingernails are one of the first places a shortfall shows.
Nails are made of keratin, which is a protein, and they grow slowly enough to keep a record. A fingernail takes around six months to grow from base to tip, so what you see today reflects how you were eating last season. When protein intake has been low for a while, I look for:
Soft, thin, or bendy nails that tear instead of snapping.
Brittle nails that split or peel in layers at the tips.
Slow growth, where you can't remember the last time you needed to trim them.
Horizontal grooves or white bands running across the nail. These tend to appear with more significant shortfalls or after a stretch of illness, and they're worth showing to your provider.
Nails rarely travel alone. Low protein often comes with thinning hair, slow-healing cuts, losing muscle, getting sick more often, and being hungry again an hour after eating.
Who runs low? In my practice, it's rarely women who "eat badly." It's women who are busy: coffee for breakfast, something light at lunch, and one proper meal at night. It's also women who are eating less on purpose, women on appetite-suppressing medications, and women who have moved toward plant-based eating without planning where the protein will come from. (No judgment on any of these. I just want your nails to stop splitting.)
And protein matters for far more than nails. It breaks down into amino acids, which are the starting material for brain chemicals like serotonin and dopamine. That's the subject of part two. For now, the simplest place to start is protein at breakfast.
Why you might be low in the first place
This is the question I care about most, because topping up a nutrient without asking why it dropped is how you end up back in the same place six months later. There are usually four possibilities.
You're not taking enough in. Skipped breakfasts, low protein, and long stretches of running on coffee add up. So do years of dieting, and eating patterns that cut out whole food groups without replacing what those foods provided.
You're losing more than you replace. Heavy periods are the big one. A woman with heavy cycles can lose iron faster than even a very good diet can put it back. Frequent blood donation and endurance training add to the tally.
You're not absorbing it well. You need enough stomach acid to absorb iron, B12, calcium, and zinc. Acid-blocking medications lower it, and chronic stress can too. Gut conditions like celiac disease, SIBO, and inflammatory bowel disease interfere further down the line. Even coffee or tea with a meal can block some of the iron in it.
You're using more than usual. Chronic stress, intense training, pregnancy, breastfeeding, and a postpartum season you never fully refilled from all raise the demand.
Most women I work with have more than one of these going on at once, which is why "just take a multivitamin" so rarely solves it.
Please don't take this list to the supplement aisle
I know it's tempting. But guessing can backfire, for two reasons. Too much of some nutrients (iron and vitamin A especially) causes real problems of its own. And nutrients compete with each other: high-dose zinc can pull down your copper, and calcium can get in the way of iron. A handful of well-meaning supplements can create a new imbalance while you're trying to fix the old one.
Here's what I'd do instead.
Notice the pattern. One sign is a shrug. Two or three together, especially alongside fatigue, low mood, or poor sleep, are worth a conversation.
Get the right labs. Ferritin with a full iron panel, vitamin D, B12, and a thyroid panel are a reasonable place to start. Your provider can add zinc, magnesium, or folate based on your symptoms.
Ask for the actual numbers. "Normal" and "optimal" aren't always the same thing, and a result at the very bottom of a reference range deserves a second look.
Ask why. Is it what you're eating, how you're absorbing it, or what you're losing?
Start with food, then supplement on purpose. The right form, the right dose, and a plan to retest in a few months.
Give it time. Skin renews in about a month, and hair and nails take several. Signs that took a year to appear won't vanish in a week.
Your body isn't being dramatic, and it isn't betraying you. It's communicating in the only language it has, and the cracked lips and restless legs are part of the message. You deserve someone who will help you read it.
If any of this sounds like your story, hit reply or leave a comment. I read every one. And if you'd like help connecting your own dots, that's exactly the kind of work we do together in the clinic.
This is part one of a three-part series. Next time: what your hormones and brain chemicals are made of, and why your meals matter more than you've been told.
Chelsie Moore, MS, CNS, LDN, is a functional medicine clinician and integrative nutritionist at Moore Integrative Health in Portland, Oregon.
This post is for educational purposes only and isn't a substitute for individualized medical advice. Please talk with your provider before starting any supplement.