Zinc Health Benefits and the Best Dietary Sources
If you have low bone density, your zinc levels could be part of the problem…
Yes, zinc is an essential mineral for bone health! Without it, you wouldn’t be able to absorb as much calcium. And that means your bones literally wouldn’t stay strong. Plus, zinc is a powerful ally in the fight against bone-damaging inflammation.
And that’s just for starters! All told, there are six science-backed ways zinc benefits your bones…
We’ll explore each of these benefits next! Then, we’ll dive into how zinc supports immunity, before revealing exactly how much you need. (No, the recommended daily allowance doesn’t cut it!)
How Zinc Benefits Your Bone Health
Supports the Bone Remodeling Process
Zinc stimulates bone growth by activating enzymes. An enzyme is a protein that triggers chemical reactions in your body. So enzymes help regulate biological processes, like bone-building!
One of the key enzymes that requires zinc is called alkaline phosphatase (ALP). And there’s a bone-specific version of ALP found on the surface of osteoblasts — the specialized cells that build bone. Bone-specific ALP plays a role in bone mineralization and is often used as a marker of bone formation.
Now, bone-specific ALP’s precise function isn’t well understood, but there’s a strong connection between this enzyme and bone formation. For example, levels of ALP are high in children undergoing rapid bone growth. Levels of this enzyme are also high during fracture healing.
Simply put, bone specific ALP is elevated when your osteoblasts are hard at work! So zinc supports bone formation by activating this enzyme.
A Note on the Other Potential Bone Remodeling Benefits of Zinc
Early research shows zinc may support other aspects of the bone remodeling process too. By “early”, I mean this research is mainly limited to cell culture and animal studies. And of course, we can’t draw conclusions from this type of research since it may not translate to humans. Nonetheless, the findings from this research are promising!
First off, zinc may increase the formation and activity of osteoblasts. Now, your osteoblasts are in charge of forming bone’s extracellular matrix, which is like a scaffolding for your bones. This scaffolding is primarily made of type I collagen — and zinc may encourage the formation of collagen as well!
In addition, zinc may slow bone resorption — the process by which bone is broken down. Cell culture and animal studies show it accomplishes this task by inhibiting two major signaling pathways: The RANKL and Tumor Necrosis Factor differentiation pathways.
These pathways both encourage osteoclasts to form. So in theory, by inhibiting these pathways, zinc regulates the amount of osteoclasts your body makes… thus slowing excessive bone resorption over time.
And there is some human research to back up this claim. In a study of 387 healthy adults, aged 55-85, researchers identified a relationship between zinc intake and bone resorption markers. But the researchers noted this relationship requires more study to be fully understood.
So overall, zinc appears to support both ends of the bone remodeling process! But of course, more high-quality human research is needed before we can confirm these last benefits.
Important Structural Component of Bone
Zinc plays a basic structural role in bone health. Your bone mineral is composed of hydroxyapatite crystals — a compound that contains several different elements and gives bones their rigid structure. And yes, zinc is one of the minerals in hydroxyapatite! So zinc is important for the very structure of your bones.
May Help Prevent Age-Related Hyperparathyroidism
Hyperparathyroidism occurs when your parathyroid glands produce excess hormones. As mentioned above, this can be triggered by low calcium levels. Now, parathyroid hormones try to make up for low calcium in two main ways:
- By triggering an increase in your body’s production of the active form of vitamin D, so you can absorb more calcium.
- By promoting osteoclast activity and bone resorption to free up calcium from bone for your body to use elsewhere.
Of course, this second function can cause serious bone loss over time. And several issues can cause hyperparathyroidism, like low calcium intake, vitamin D deficiency, and malabsorption of nutrients.
But parathyroid hormone levels also tend to naturally increase with age in both men and women. For a long time, this was a bit of a mystery… until researchers suggested that insufficient zinc may be one of the reasons for age-related increase in parathyroid hormone levels. Why?
Zinc may stabilize the membrane of a type of immune cell called mast cells. This helps prevent the release of heparin, a naturally occurring anticoagulant. (That means it inhibits the coagulation of blood.) Now, heparin appears to be a cofactor for parathyroid hormone. A cofactor is like a “helper molecule” that aids chemical reactions.
So the theory is zinc deficiency can lead to an increase in heparin, as well as a pro-inflammatory molecule called prostaglandin E2. And both heparin and prostaglandin E2 are likely cofactors for parathyroid hormone. (In other words, they trigger the release of parathyroid hormone!) In this way, a zinc deficiency can mimic hyperparathyroidism and cause bone loss as you age.
But note this theory is primarily based on data from observational studies. That means, researchers have found a correlation between zinc, heparin, prostaglandin E2, and osteoporosis, but they haven’t shown causation. So this function requires more study!
Helps Protect Against Heavy Metals
Heavy metals are a type of environmental toxin. They can be found naturally in certain foods, cleaning products, and even the water supply. And these toxins can wreak havoc on your bones. (For more information on environmental toxins and their effects on bone health, visit our “Top Causes of Osteoporosis” page.)
But zinc helps protect against these negative effects in several ways. For starters, zinc is technically a metal, so it competes with heavy metals like cadmium and lead for binding sites. This reduces the amount of these metals taken up by cells and helps protect against heavy metal poisoning.
Zinc also causes the production of a protein called metallothionein (MT). And MT binds to heavy metals, which prevents them from being taken up by cells and helps detoxify your body.
Finally, zinc alleviates oxidative stress caused by heavy metal exposure. Oxidative stress can lead to bone loss by triggering chronic, low-grade inflammation. And zinc is a cofactor for an antioxidant called copper zinc-superoxide dismutase that helps fight oxidative stress. (Note this isn’t the only way zinc fights oxidative stress… more on this in the next section!)
Required to Produce the Active Form of Vitamin D
You need zinc to produce 1,25-D — the active form of vitamin D. Without 1,25-D, you can’t actively absorb calcium from your digestive tract. So a lack of zinc impairs calcium absorption, which promotes bone loss.
This can also trigger hyperparathyroidism (a condition when your parathyroid glands are overactive), because when calcium absorption plummets, your body reacts by producing more parathyroid hormones. More on how this condition affects your bone health next!
Lessens Inflammation by Acting as an Antioxidant
Zinc functions as an antioxidant in several ways. And antioxidants fight oxidative stress that causes bone-damaging inflammation!
First off, zinc inhibits a group of enzymes that trigger the production of reactive oxygen species (ROS) — the agents of oxidative stress. So by inhibiting the creation of ROS, zinc decreases oxidative stress.
As we covered earlier, zinc is a cofactor for copper zinc-superoxide dismutase. Now, this antioxidant triggers the “dismutation” of ROS. Dismutation is a chemical reaction where a compound is reduced and oxidized. In plain English, that means superoxide dismutase breaks down ROS.
Zinc also increases the production of anti-inflammatory zinc-containing proteins. These are called zinc finger proteins!
Finally, zinc boosts the activity of several antioxidant proteins, molecules, and enzymes such as glutathione. Glutathione is a powerful antioxidant that also regenerates other important antioxidants like vitamins C and E.
As you can see, zinc’s antioxidant functions are extensive, and they go beyond the main ones mentioned here. So it comes as no surprise that in human studies, supplementing with zinc decreases oxidative stress and levels of inflammatory signaling molecules called cytokines. In this way, zinc reduces inflammation and protects against excess osteoclast activation and bone loss!
Human Studies of Zinc and Bone Health
Now, we’ve seen all the ways zinc supports bone health! Some of these benefits are established, while a few require more study. Nonetheless, we can tell a lot by looking at what happens to bone health in humans when zinc levels are low versus high.
In one study of postmenopausal women with osteoporosis and osteopenia, dietary intake of zinc was assessed alongside calcium, copper, and magnesium. The researchers found that participants had significantly lower levels of zinc and copper than the normal range for your average person. Now, this was a small study, and more than just zinc was at play… but the results suggest zinc is one of several nutrients you need for healthy bones.
In another larger study, researchers looked at the relationship between bone mineral density (BMD) and mineral levels of 728 postmenopausal women. This time, there was a significant relationship between low zinc levels and osteoporosis in the spine. The researchers concluded that low zinc appears to be an important risk factor for osteoporosis. Now, this study showed correlation, not causation. And again, more minerals were assessed than just zinc! But like the previous study, the results suggest zinc is key for bone health — while also highlighting the importance of a multi-nutrient approach.
Perhaps most notably, in a recent study of 3607 participants, zinc levels were assessed in relation to several health outcomes.The researchers found zinc levels were significantly associated with increased BMD in the spine and femur of participants. Of course, we’re still talking about correlation, not causation… but the evidence in favor of zinc’s beneficial effects on bone is starting to stack up!
Now, these last three studies show a correlation between zinc and bone health. But to establish causation, we need to look at a clinical trial, not an observational study. And there is one double-blind, randomized, placebo-controlled trial worth mentioning…
This study included 32 participants with a condition called thalassemia — a blood disorder that leads to anemia. Patients with thalassemia often have low zinc levels, which has been associated with low bone density. So researchers investigated whether receiving 25 mg of zinc or a placebo for 18 months would affect bone mass. And they found zinc supplementation led to bone mass gains compared to placebo! Now, this was a small study, but the study design lends weight to its findings…
So even though more research is warranted, several human studies do support zinc’s bone protective effects!
Other Health Benefits of Zinc
Zinc is perhaps most well-known for its role in immune system health. And with good reason! This mineral influences every aspect of immunity…
Let’s take a closer look:
Supports All Aspects of Immune Function
Both your innate and adaptive immune systems require zinc to function.
Your innate immune system is your first line of defense against infection. It’s in charge of immediate and nonspecific responses like inflammation, fever, and engulfing invading pathogens. It also encompasses barriers like your skin and mucous membranes.
Your adaptive immune system is your second line of defense and develops a specific response to pathogens. So it can take a little longer to deploy, and it involves specialized T- and B-cells.
Now, you need zinc on a basic level for the growth and development of all your immune cells! What’s more, zinc is key for immune cell functions and signaling. In other words, it helps your immune systems communicate and triggers immune cell activities.
As we’ve seen, zinc also functions as an antioxidant by reducing oxidative stress. Your innate immune response generates oxidative stress to deal with invaders, but this process can damage your body’s cells. So basically, zinc protects your immune system from itself!
There’s a wealth of research that backs up zinc’s importance for the immune system too. In fact, if you search “zinc and the immune system” in PubMed, a comprehensive database of scientific studies, you’ll get over 5000 results!
What’s more, in a detailed scientific review, researchers found that zinc supplementation reduces the risk of infection and promotes immune response in older adults. Yet another reason to ensure you get plenty of zinc. (We’ll go over how much is ideal in a moment.)
If you’d like to read more about zinc’s specific role in immune system health, visit this page and scroll down to the section on zinc.
Regulates the Wound Healing Process
Zinc helps regulate every phase of the wound healing process! This makes sense when you consider that wound healing, inflammation, and the immune response are all closely linked. And as we’ve seen, zinc plays many roles in the immune response and inflammation.
What’s more, your skin contains about 5% of your body’s total zinc content. So it helps keep your skin and mucosal membranes strong. This explains why there are many zinc skincare products on the market! And why, even mild zinc deficiency can lead to rough skin and impaired wound healing.
Treating a zinc deficiency, on the other hand, has been shown to improve wound healing compared to those who didn’t receive the treatment. But for folks who aren’t zinc deficient, the benefits of supplementation are less clear, as there are few high quality studies on the topic.
That said, a surprising amount of the population may be zinc deficient! We’ll discuss why this might be, and how to make sure you’re getting enough next…
How Much Zinc Do You Need?
The recommended daily allowance (RDA) for zinc is 8 mg for women 19 years and older and 11 mg for men 19 years and older.
Now, these recommendations are for adequate, not optimal intake. What’s more, research suggests adults aged 60 and older consume less than 50% of the RDA! So your zinc levels may be quite low to begin with.
With this in mind, the recommendation you’ll want to pay attention to is 15 mg of zinc a day.
Why 15 mg? Well, a comprehensive review of the research on zinc shows this is the amount necessary to support bone health. And since the tolerable upper limit for zinc is 40 mg a day, you can safely consume 15 mg. But note that several factors can affect zinc intake, so you may need even more than this. (We’ll go over these factors in a moment!)
Now, AlgaeCal Plus does contain a small amount of zinc (24.1 mcg), so it’s a nice complement to your daily intake! But of course, you’ll want to ensure you include plenty of zinc-rich foods in your diet too…
Best Food Sources of Zinc
The best sources of zinc are high protein foods like seafood and red meat. And like zinc, protein is key for strong, healthy bones. So there’s an added benefit to eating zinc-rich foods!
To get you started, here’s a list of 22 foods high in zinc:
|Percent Daily Value (DV)|
|Oysters, cooked, breaded and fried, 3 ounces||74.0||673|
|Beef chuck roast, braised, 3 ounces||7.0||64|
|Crab, Alaska king, cooked, 3 ounces||6.5||59|
|Beef patty, broiled, 3 ounces||5.3||48|
|Lobster, cooked, 3 ounces||3.4||31|
|Pork chop, loin, cooked, 3 ounces||2.9||26|
|Baked beans, canned, plain or vegetarian, ½ cup||2.9||26|
|Breakfast cereal, fortified with 25% of the DV for zinc, 1 serving||2.8||25|
|Chicken, dark meat, cooked, 3 ounces||2.4||22|
|Pumpkin seeds, dried, 1 ounce||2.2||20|
|Yogurt, fruit, low fat, 8 ounces||1.7||15|
|Cashews, dry roasted, 1 ounce||1.6||15|
|Chickpeas, cooked, ½ cup||1.3||12|
|Cheese, Swiss, 1 ounce||1.2||11|
|Oatmeal, instant, plain, prepared with water, 1 packet||1.1||10|
|Milk, low-fat or non fat, 1 cup||1.0||9|
|Almonds, dry roasted, 1 ounce||0.9||8|
|Kidney beans, cooked, ½ cup||0.9||8|
|Chicken breast, roasted, skin removed, ½ breast||0.9||8|
|Cheese, cheddar or mozzarella, 1 ounce||0.9||8|
|Peas, green, frozen, cooked, ½ cup||0.5||5|
|Flounder or sole, cooked, 3 ounces||0.3||3|
Factors That May Affect Your Zinc Intake
Your body contains just two to three grams of zinc. You naturally lose about 0.1% of this amount a day, which equals 20-30 micrograms (mcg). Given how small this loss is, you’d think maintaining your zinc levels would be easy… but often, it’s not!
That’s because there may be other factors at play:
What You Eat
There are two main dietary factors that could be getting in the way of your zinc intake.
1) Eating too many foods high in phytate
Many plant foods, particularly cereals, nuts, and legumes, contain compounds called phytates. Phytates are compounds that bind to minerals (including zinc!) and prevent absorption. So if you eat a lot of these types of foods, you may be at risk of zinc deficiency.
Thankfully, there are some methods to increase your absorption of zinc from plant foods. Soaking cereals and legumes overnight can help reduce phytate content. (This is one of the reasons it’s recommended you soak your beans!)
Sprouting (also called germination) is another method that’s gained popularity in recent years. This is a process where you allow seeds, grains, or legumes to soak for several days. Then, you drain them and leave them to germinate until they sprout. The resulting edible sprouts have lower phytate content.
Finally, fermentation also promotes phytate breakdown. Fermentation is basically a chemical process where a substance is broken down by bacteria or yeast. This sounds complicated, but if you’ve ever made your own gluten-free bread or pizza dough, you’ve used fermentation.
2) Not eating enough zinc-rich foods like red meat
The other dietary risk factor for zinc deficiency is not eating enough seafood and red meat. As we’ve seen, seafood and red meat are the richest sources of zinc. What’s more, zinc is better absorbed from animal foods than from plant foods. (Yes, phytate content is a primary reason for this!)
That’s why vegetarians and vegans are at higher risk of zinc deficiency. If you’re a vegetarian, your risk is slightly lower because dairy products provide a bit of zinc. Regardless, both vegetarians and vegans should be especially vigilant of their zinc intake.
How Well You Digest and Absorb Nutrients
During digestion, your stomach acid and pancreatic enzymes break down food into smaller zinc-containing peptides. (Peptides are short chains of amino acids.) But if you’re not producing enough stomach acid or enzymes, your ability to break down food is compromised. That means, you won’t be able to properly digest and absorb zinc!
This is often the case in conditions like inflammatory bowel disease, Crohn’s disease, or if you’ve had gastric bypass surgery. So if you suffer from malabsorption, you may want to consider supplementing your zinc intake.
Your Level of Inflammation
Your zinc needs increase when you’re fighting an infection. This is because zinc is key for your immune response. And that includes fighting inflammation…
Your zinc needs will be even greater if you have a condition that chronically increases your level of inflammation such as asthma, inflammatory bowel disease, or kidney disease. Again, as we’ve seen, zinc helps reduce inflammation. So it makes sense that those with chronic inflammation would require more zinc!
The main takeaway: There are many factors that affect zinc intake, so even though the recommendation for healthy bones is 15 mg a day, you may need more! Just keep in mind that the tolerable upper limit for adults is 40 mg.
Zinc Side Effects
If you stick below the tolerable upper limit of 40 mg a day, zinc is quite safe.
But there’s one caveat: You need to balance your intake of zinc with copper. Specifically, you should aim for a ratio of zinc to copper of 15:1. That means, if you get the recommended 15 mg a day of zinc for bone health, you need 1 mg of copper.
This is perfect since the RDA for copper is 900 mcg (0.9 mg). So to balance your zinc, you’d get a little more copper than the average requirement… but still well within the tolerable upper limit for copper of 10 mg.
This balance is important for two reasons:
- Long-term consumption of zinc at more than 40 mg a day can cause a copper deficiency. This can inhibit the activity of the antioxidant we discussed earlier, copper zinc superoxide dismutase. When you consider this antioxidant needs both zinc and copper… and excess zinc causes a copper deficiency… this all makes sense.
It’s also worth noting that copper supports your health in many ways — and that includes your bone health. So you don’t want to deprive your bones of this mineral either!
- Excessive copper intake compared to zinc can increase oxidative stress. And of course, oxidative stress leads to inflammation and bone loss. Plus, as we’ve seen, your inflammation levels affect your zinc needs. So this can further reduce your zinc levels in relation to copper.
As you can see, it’s a fine balance when it comes to zinc and copper! But don’t worry too much… copper is harder to come by in foods than zinc, so your diet should naturally lend itself to this balance.
It’s also worth noting that zinc is sometimes prescribed at higher amounts for medical treatment. But in these instances, individuals are under the care of a medical professional who will closely monitor them for adverse health effects.
Zinc’s status as an essential trace mineral is well-deserved…
In fact, one study asserts “zinc is essential for virtually all processes in the human body”!
This encompasses everything from growth and development to immune function. And as we’ve seen, zinc has a lot to offer your bones too!
Zinc is important for both the structure and formation of bone. It offers protective effects against inflammation, hyperthyroidism, and heavy metals. And last but not least, it helps you convert vitamin D into the active form needed to absorb calcium.
So it’s worth making an effort to get the optimal daily intake for bone health of 15 mg a day.
AlgaeCal Plus contributes a small amount to this intake, as well as everything else you need for strong, healthy bones. In fact, three clinical studies show it’s the only calcium supplement that can increase bone density, at any age!
For more information on AlgaeCal Plus, click on the banner below: