Zinc is an essential mineral that plays many important roles in the body. Consuming too much zinc on a regular basis can cause health problems. The recommended daily amount of zinc is 11mg for adult males and 8mg for adult females. So at 50mg per day, most people would be getting significantly more than the recommended amount.
For most healthy adults, 50mg of supplemental zinc per day is likely too much. The recommended upper limit for zinc is 40mg per day. Consuming more than this over an extended period can lead to copper deficiency, impaired immune function, and other problems.
How Much Zinc Do We Need?
The recommended dietary allowance (RDA) for zinc is:
- 11mg per day for adult males
- 8mg per day for adult females
- 9-13mg for children depending on age
- 11-12mg for pregnant women
- 12-13mg for breastfeeding women
These RDAs are the average daily amounts of zinc that meet the needs of over 97% of healthy individuals in certain age and gender groups. Consuming less than the RDA increases the risk of zinc deficiency.
In addition to the RDA, there is also a tolerable upper intake level (UL) for zinc:
- 40mg per day for adults
- Lower levels for children depending on age
The UL is the maximum amount that can be consumed from food and supplements without posing significant risk of adverse health effects in most individuals.
Zinc Benefits and Roles
Zinc has many crucial roles in the body and is essential for good health. Some of zinc’s key benefits and functions include:
- Immune function – Zinc is vital for immune cell development and communication. Even mild zinc deficiency can negatively impact immunity.
- DNA and protein synthesis – Zinc enables cells to divide and synthesize proteins. Every cell in the body depends on zinc.
- Wound healing – Zinc assists in the rapid renewal of skin and other tissues following injury.
- Growth and development – Zinc is especially important for children’s growth and adolescents’ maturation.
- Taste and smell – Zinc is needed for proper sense of taste and smell since it enables enzyme function in these pathways.
- Fertility and reproduction – Zinc impacts fertility in both males and females, plus fetal development during pregnancy.
- Thyroid function – Zinc is required for the production, synthesis, and activation of thyroid hormones.
- Vision health – Zinc is concentrated in the eye, particularly the retina, and is necessary for vision nerve signaling.
- Blood clotting – Zinc supports normal blood clotting by keeping platelet adhesion in balance.
Given all of zinc’s vital roles, it’s clear that adequate zinc intake is crucial for maintaining good health.
Because of widespread zinc deficiency around the globe, zinc may be the most common micronutrient deficiency in the world. It’s estimated that more than 15% of people worldwide have inadequate zinc intake or absorption.
Groups most at risk of zinc deficiency include:
- Those with malnutrition or food insecurity
- Vegans and vegetarians (due to lower zinc bioavailability)
- The elderly
- Those with digestive disorders like Crohn’s disease
- Strict dieters
- Pregnant women
Even mild zinc deficiency can negatively impact health. Symptoms of mild zinc deficiency include:
- Frequent colds, flu, and infections
- Poor wound healing
- Hair loss
- Eye and skin lesions
- Loss of appetite
- Impaired cognition and attention
Symptoms of more severe zinc deficiency include severe infections, stunted growth in children, and delayed sexual maturation in adolescents. Severe zinc deficiency is rare in developed countries but remains a major public health issue in parts of the developing world.
Zinc Toxicity and Overdose
Although zinc deficiency is far more prevalent than zinc excess, consuming very high amounts of zinc for prolonged periods can also cause problems. The upper limit for zinc is 40mg per day for adults. Regularly exceeding the UL raises the risk of zinc toxicity.
Potential effects of zinc overdose include:
- Copper deficiency – High zinc impairs copper absorption by competing for absorption in the digestive tract. Copper deficiency leads to anemia, bone abnormalities, and heart complications.
- Immune dysfunction – While zinc benefits immunity, too much zinc can actually suppress immune cell activity and function.
- Nausea and vomiting – Stomach irritation is common with excessive zinc intake.
- Changes in cholesterol – High zinc may adversely affect cholesterol balance, raising LDL and lowering HDL.
- Kidney problems – Zinc toxicity has been associated with kidney stones and reduced kidney function.
Intakes of 150-450mg zinc per day have been found to cause these toxic effects in some people, especially if maintained long term.
Acute zinc toxicity is rare and usually caused by the accidental consumption of zinc-containing coins or other metal objects. Symptoms include severe stomach pain, vomiting, diarrhea, kidney failure, and even death.
Dietary Sources of Zinc
The best sources of zinc from foods include:
- Oysters – 74mg per serving
- Beef – 7mg per 3 ounces
- Crab – 6.5mg per 3 ounces
- Lobster – 3.4mg per 3 ounces
- Pork – 2.2mg per 3 ounces
- Chicken – 1.4mg per 3 ounces
- Milk – 1mg per cup
- Beans – 1-1.5mg per half cup
- Yogurt – 1mg per cup
- Cashews – 1.6mg per ounce
Grains and vegetables are not very dense in zinc. Absorption of zinc from plants is also lower due to the presence of phytate, which binds zinc.
For strict vegetarians and vegans, maintaining adequate zinc from diet alone can be challenging. Supplementation may be beneficial for these groups.
Taking zinc supplements can help prevent or treat deficiency, especially in at-risk groups. Supplements may also be used by those looking to maximize zinc’s immune boosting effects.
The two main forms of zinc supplements are:
- Zinc gluconate – Typically used in cold remedies and lozenges for the throat. Absorbed well but can cause stomach irritation.
- Zinc picolinate – More easily absorbed and less likely to cause side effects. Used in most standard zinc supplements.
General zinc supplement recommendations are:
- Deficiency treatment – 60-120 mg per day, divided into smaller doses
- Routine supplementation – 15-30mg per day to meet RDA
- Immune support – up to 50mg per day for short periods
People taking zinc long term should also supplement 1-2mg copper to prevent deficiency. Zinc should be taken with food to minimize side effects.
Is 50mg of Zinc Per Day Too Much?
For healthy adults, a daily zinc dose of 50mg is likely too much and may lead to zinc excess with prolonged use. While the upper limit is 40mg, there is also risk of toxicity above levels closer to the RDA.
According to research:
- Doses over 50mg per day have been found to negatively alter HDL, LDL, and total cholesterol levels.
- Intakes between 50–100 mg/day have impaired immune cell function and reduced levels of good HDL cholesterol.
- One study found 60mg per day increased inflammation and oxidative stress.
- Doses of 50mg have interfered with copper absorption, even when copper was also supplemented.
Those taking zinc supplements for general immune support or prevention of deficiency should not exceed 30mg per day unless advised to by a doctor.
People with zinc deficiency may need 50-60mg temporarily under medical supervision. But this dosage should not be maintained long term once the deficiency is resolved.
Certain groups like athletes and the elderly may benefit from 25-50mg daily. But even in these cases, breaks should be taken to allow copper levels to recover.
High dose zinc should only be used short term for targeted therapeutic purposes like treating a cold. Prolonged intakes over 40mg per day are not recommended without medical guidance.
Some additional factors to keep in mind when it comes to high dose zinc supplementation:
- Zinc absorption decreases as dosage increases. The body absorbs zinc best at doses of 15-30mg.
- Zinc competes with other minerals for absorption. Excess zinc impairs iron, copper, and magnesium uptake.
- Zinc is best absorbed on an empty stomach. But this also increases potential for stomach irritation.
- Zinc taken with food has lower absorption, but fewer side effects.
- Timing matters. Once per day dosing maximizes absorption. Intakes spread throughout the day are ideal.
- Different forms have varying absorption and potency. Zinc picolinate is highly bioavailable.
These factors make determining the ideal zinc dose complex. Nailing down exactly how much is too much is difficult. But intakes consistently over 40mg appear more likely to cause harm than benefit in those who are zinc replete.
Signs of Zinc Excess
Potential signs that zinc intake may be too high include:
- Stomach cramps
- Metallic taste in mouth
- Copper deficiency symptoms – neurologic issues, anemia
- Weakened immune function
- Low HDL, high LDL cholesterol
- Kidney stones
Those taking high dose zinc supplements should watch for these signs and adjust dosage down if they develop. Seeking professional medical advice is recommended as well.
Special Considerations for High Zinc Intake
Certain groups should be especially cautious with high zinc intake:
- Pregnant women – Excess zinc is teratogenic and associated with birth defects. High maternal zinc also causes copper deficiency in the newborn.
- Those with weakened immunity – The elderly and chronically ill rely on zinc’s immune benefits, but are also more susceptible to toxicity risks.
- Individuals taking antibiotics – Quinolone and tetracycline antibiotics interact with zinc, requiring dose reduction.
- People with kidney disorders – Impaired kidney function increases likelihood of toxicity from excessive zinc.
For these groups, intakes above 30-40mg daily should be avoided unless medically advised. Lower zinc doses are likely safer and sufficient.
The Bottom Line
In summary, while zinc is an essential mineral, too much can be harmful. Here are some key points on whether 50mg per day is too much zinc:
- The recommended upper limit for zinc is 40mg for healthy adults.
- Most people meet zinc needs through diet alone or with a modest supplement of 15-30mg.
- Doses of 50mg may impair immunity, cholesterol, and copper status with prolonged use.
- Intakes of 50mg could be appropriate short term for therapeutic purposes like combating a zinc deficiency.
- Those taking zinc long term should not exceed 30mg per day unless directed to by a doctor.
- Signs of excessive zinc include nausea, copper deficiency, and weakened immunity.
- Special care should be taken with high zinc doses in those with medical conditions or taking medications that interact with zinc.
In conclusion, while no set number defines too much zinc for everyone, regular intakes over 40mg provide little additional benefit, and may raise the risk of adverse effects. Moderation is advised when it comes to supplemental zinc.