Zinc: Benefits, Food Sources, & Signs of Deficiency

Originally posted January 2018 / Updated October 2024

Have you ever felt exhausted, noticed persistent skin issues, or experienced mood swings that leave you wondering? Many symptoms might be linked to a deficiency in zinc—a vital trace mineral essential for overall health. 

This article will explore the multiple benefits of zinc, common deficiencies, and how they can affect human health. We’ll also explore the different types of zinc supplements available, helping you make better decisions about your wellness journey.

Function of Zinc

Zinc is essential for DNA synthesis, cell division, and immune system function. The average body has 2-3 grams of zinc, usually bound to proteins. In addition, zinc is involved in over 300 biochemical reactions in the body, indicating its importance. 

Zinc’s Role In Your Body

• Fights the common cold
• Helps reduce acne
• Optimizes memory and brain health
• Reduces risk of depression 
• Helps Attention Deficit Hyperactivity Disorder (ADHD/ADD)
• Helps those with Traumatic Brain Injury (TBI)
• Helps with wound healing
• Prevents sunburns
• Helps prevent diarrhea in children 6 months or older
• Optimizes immune system
• Optimizes protein synthesis
• Optimizes DNA health
• Helps cells to reproduce appropriately

Health Benefits of Zinc

• Brain Health - Zinc is essential for brain health; adequate levels may improve mood and memory. Low levels have been linked with developmental conditions like ADHD.
• Immune Function - Zinc is critical for the development and function of healthy immune cells. Research suggests that zinc may help reduce the duration and severity of cold symptoms, particularly when taken within 24 hours of onset Supplementation may reduce the incidence of infections, especially in the elderly².
• Skin Health - Zinc is vital for the growth and development of skin cells. Its anti-inflammatory properties also promote faster wound healing⁷ Conditions like acne and eczema have been associated with low zinc levels. Taking zinc supplements can enhance skin health and optimize wound healing³.
• Low Testosterone - A common problem in men, especially as they age. Therefore, testing for zinc and when testosterone deficiency is present may be beneficial.
• Chronic Inflammation - Common in those with diabetes and heart disease, may be made worse when blood levels of zinc are low, according to a 2012 study. Inflammation is believed to be a precursor to many chronic health issues. 

Food Sources of Zinc

The good news is that you can boost your zinc levels by incorporating zinc-rich foods into your diet. Here are some excellent food sources, along with their approximate zinc content:

Best Food Sources of Zinc  (per 3 grams of food) 

• Oysters – 74 mg 
• Beef Chuck Roast – 7 mg 
• Alaska Crab – 6.5 mg 
• Beef Patty – 3 mg 
• Breakfast cereal – 3.5 mg 
• Lobster – 3.4 mg 
• Pork chops – 2.9 mg 
• Baked Beans – (1/2 cup) 2.9 mg 
• Chicken – 2.4 mg 
• Fruit yogurt – (1 cup) 1.9 mg 

Zinc Deficiency

Zinc deficiency is more common than many realize and often goes undiagnosed. According to studies, up to 17% of the world’s population is zinc deficient, with prevalence varying by age, gender, and dietary habits. Up to 30% of people with absorption issues, such as colitis or weight loss surgeries, are deficient, according to studies. Another study of women worldwide indicated up to 15-73% of pregnant women could be lacking in this vital mineral.

• Children and Adolescents: Infants and young children are particularly at risk since they require higher amounts of zinc for growth and development. In developing countries, it is estimated that 20% of children may be zinc deficient.
• Adults: Among older adults, especially those with chronic illnesses, the incidence of zinc deficiency is roughly 31%. This is due to lower dietary intake and reduced absorption. In my medical practice, I have diagnosed hundreds of patients, mostly elderly, with zinc deficiency, which allowed me to help get to the root cause of their health concerns. 

One way to test for zinc deficiency is through a serum zinc test, which measures zinc concentration in your blood. Alternatively, a more comprehensive assessment might include hair or urine analysis¹.

Symptoms Of Zinc Deficiency

Zinc deficiency can contribute to many health issues, including:

• Impaired Immune Function: Making you more susceptible to infections.
• Anosmia: Lost ability to smell
• Hair Loss: Thinning hair or increased hair loss.
• Diarrhea: Due to impaired immune response in the gut.
• Delayed Wound Healing: Cuts and bruises take longer to heal.
• Taste Abnormalities: Changes in your sense of taste or loss of appetite.

Physical Signs of Zinc Deficiency

• White Spots on Fingernails
• Slow-Healing Wounds
• Hair Loss or Thinning
• Frequent Infections
• Skin Lesions or Dermatitis, Particularly Around the Mouth and Eyes
• Inability to smell aromas

Medications Contributing to Zinc Deficiency

Certain medications can deplete zinc levels in your body, including:

• Diuretics (e.g., furosemide hydrochlorothiazide, chlorthalidone), commonly used to treat high blood pressure, heart failure and fluid retention Acid Reducers (e.g., omeprazole. Pantoprazole, esomeprazole) can result in reduced absorption 
• ACE Inhibitors (e.g., lisinopril, benazepril) used to treat high blood pressure
• Drugs for Rheumatoid Arthritis (e.g., methotrexate)
• Antibiotics (e.g., tetracycline and quinolone (ciprofloxacin, levofloxacin) antibiotics): Zinc can bind with these medications, decreasing their absorption. Taking zinc supplements at least two hours apart from these antibiotics is recommended if you are currently being treated for an infection.

If you’re taking these medications, talking to your doctor about your zinc levels is prudent. They might recommend dietary adjustments or supplementation to help mitigate the risk of deficiency. Also, consider asking your physician to check your blood and measure your zinc level. 

Types of Zinc

If you’re considering supplementation, choosing the right type of zinc is essential. There are many different choices, each one a little different. To help you decide, here are some common forms, along with the pros and cons of each:

Zinc Gluconate

• Pros: Well-absorbed and commonly used in tablets for cold treatment.
• Cons: Lower zinc content compared to other forms of zinc.

Zinc Picolinate

• Pros: Highly bioavailable, meaning the body absorbs it more efficiently.
• Cons: Often higher priced.

Zinc Citrate

• Pros: Better absorption rate than zinc oxide.
• Cons: Contains less elemental zinc than some other forms.

Zinc Oxide

• Pros: Widely available and inexpensive.
• Cons: Lower absorption rate than other forms.

Choose a supplement that suits your needs and consider discussing it with a healthcare provider for personalized advice. 

Recommended Daily Allowance and Optimal Dose

The Recommended Dietary Allowance (RDA) for zinc varies by age and gender:

• Men (19 years and older): 11 mg/day
• Women (19 years and older): 8 mg/day
• Pregnant Women: 11 mg/day
• Lactating Women: 12 mg/day

The levels listed are the bare minimum needed for one to function. However, the optimal dose can vary depending on individual health needs and existing deficiencies. For general health maintenance, the RDA is typically adequate. However, therapeutic doses may range from 25 mg to 50 mg per day for specific conditions like immune support. Always seek expert guidance when considering higher doses.

Zinc Toxicity

While zinc is essential, too much can be harmful. It is important to take the recommended dose on the label. Excessive intake can lead to toxicity, with symptoms such as:

• Diarrhea
• Nausea and Vomiting
• Impaired Immune Function

Also, it is essential to note that chronic high doses can interfere with copper absorption, leading to copper deficiency¹⁰. Sticking to recommended dosages is vital unless advised otherwise by a healthcare professional.

Conclusion

Zinc is an essential mineral that plays a vital role in many aspects of health, including immune function, skin care, cognitive abilities, and mood balance. As a family physician, I encourage everyone to ensure they maintain healthy zinc levels, either through their diet or with supplements, especially if they’re at risk of deficiency.

However, before starting any new supplement, it's always a good idea to talk to your healthcare provider to make sure it's the right choice for you since everyone’s needs can vary. Getting the right amount of zinc could be a key factor in improving your overall health—sometimes it’s the small things that make a big difference!

References:

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