1. Dry & Itchy Skin
One of the most common signs of omega-3 deficiency is dry, flaky, or itchy skin. Omega-3s are critical in maintaining the skin's barrier, which helps retain moisture (6, 7). Without enough omega-3s, the skin becomes more susceptible to dehydration, leading to irritation, itching, and flakiness. In fact, omega-3 has been shown to provide benefits for mild dermatitis (eczema), dry skin conditions, and acne, as well as protect against sun damage (8).
One small study gave women a daily dose of of ALA-rich flaxseed oil for 3 months. The results? Women who took the flaxseed oil experienced decreased skin roughness and increased skin hydration, compared with those who received a placebo (9).
Another 20-week study gave omega-3-rich hempseed oil daily to people with eczema. Participants experienced reduced dryness and itchiness and needed less topical medication (10).
Additionally, experiencing more acne than normal may be an indirect indication of omega-3 deficiency in some people (11). Research has shown that taking omega-3 supplements can help reduce acne breakouts and skin inflammation (12, 13).
Interestingly, some studies have also found that taking EPA and DHA supplements may reduce how sensitive your skin is to ultraviolet light. In one study, participants who took 4 grams of EPA daily for 3 months experienced a significant increase in their resistance to sunburn (14, 15).
If you’ve been struggling with dry skin despite moisturizing, a lack of omega-3s could be the culprit.
2. Dull Hair or Hair Loss
Skin and hair health go hand in hand. And just like skin, healthy hair requires omega-3s to stay shiny, smooth, and strong. Omega-3s nourish the hair follicles, support scalp health, and prevent inflammation that could cause hair thinning or hair loss.
A deficiency in omega-3s can lead to dry, brittle, and dull-looking hair. In more severe cases, you may even notice an increase in hair shedding or thinning.
One 6-month study gave 120 female participants omega-3s, along with omega-6 fats and antioxidants, in a daily supplement. At the end of the study, those who had taken the supplement experienced reduced hair loss and increased hair density compared with the control group (16).
If you’re experiencing increased hair loss or have noticed that your hair is thinning or feeling dry and brittle, taking an omega-3 supplement may help.
3. Dry Eyes
Omega-3s are known to support the production of natural oils in the eyes, which keep them moist and comfortable. When you're deficient in omega-3s, you might experience dry, irritated, or even itchy eyes.
This can lead to discomfort, especially in people who wear contact lenses or spend a lot of time staring at screens. Omega-3s, especially DHA, are critical for maintaining healthy vision and preventing dry eye syndrome.
One study of 64 adults with dry eye looked at the effects of taking omega-3s (17). One group of participants consumed two daily capsules, each containing 180 mg of EPA and 120 mg of DHA. The other group of participants took a placebo.
After 30 days, those who had taken omega-3 supplements experienced less tear evaporation, improved dry eye symptoms, and more tear production.
4. Brittle Nails
If your nails seem weak, brittle, or prone to splitting, it might be a sign that your omega-3 intake is too low. Omega-3s play a role in maintaining nail health, as they help to keep the nails strong and resilient by nourishing the nail bed. Without adequate omega-3s, nails can become fragile and easily damaged (18).
5. Joint Pain
Omega-3 fatty acids are well-known for their anti-inflammatory properties. When levels are too low, you may experience increased inflammation, which can manifest as joint pain or stiffness. Omega-3s, especially EPA and DHA, help to reduce inflammation in the body, potentially easing discomfort associated with conditions like arthritis.
Some studies have found that taking omega-3 supplements helps reduce joint pain and increase grip strength (19). Research also shows that fatty acids may help with osteoarthritis, though more human studies are needed (20, 21).
If you've noticed a worsening of joint pain, particularly if it coincides with a change in diet or lifestyle, omega-3 deficiency could be playing a role.
6. Poor Sleep Quality
The connection between omega-3s and sleep is less commonly discussed, but research has shown that these essential fats help regulate the production of melatonin, the hormone responsible for sleep-wake cycles.
Low levels of omega-3s have been linked to problems falling and staying asleep, as well as poorer overall sleep quality (22). Restoring omega-3 levels might help improve both the duration and quality of sleep.
Native Note: If you’re struggling to fall asleep, here are 15 highly effective tips to help you get the deep, restorative sleep you deserve.
7. Fatigue
Chronic fatigue or feeling constantly low on energy could be a subtle sign of omega-3 deficiency. Omega-3s are vital for maintaining cellular energy production, and without enough of these fats, your body might struggle to function at its best (23).
Fatigue, especially if it’s paired with other symptoms on this list, may indicate that you’re not getting enough omega-3s in your diet.
8. Brain Fog
Omega-3s, particularly DHA, are crucial for brain health. They support cognitive function, memory, and even emotional well-being (24, 25). When omega-3 levels drop, you may start to notice problems with concentration, memory lapses, or a general feeling of mental "fuzziness," commonly referred to as brain fog.
A deficiency in omega-3s could also exacerbate symptoms of anxiety and depression, further affecting mental clarity.
9. Mood Swings & Irritability
In addition to brain fog, omega-3 deficiency has been linked to emotional instability. Low levels of omega-3s can disrupt the balance of neurotransmitters in the brain, leading to mood swings, increased irritability, and even symptoms of depression (26).
Research has shown that omega-3s can help stabilize mood, so maintaining adequate levels is essential for mental health and emotional well-being (27).
One analysis of 26 studies that included 2,160 participants found that taking omega-3 supplements had a beneficial effect on depressive symptoms. Specifically, an omega-3 supplement that contained at least 60% EPA, taken at a dosage of 1 gram or less per day, appeared to be helpful (28).
Another systematic review and analysis of 6 studies and 4,605 participants concluded that daily omega-3 intake significantly reduced mild to moderate depression symptoms (29).
