Is Zinc Good for Hair Growth? Here's What the Science Says

There are dozens of vitamins and minerals that each play an important role in different areas of your health. Zinc is one of these essential minerals, and while it’s often overlooked, it’s crucial for immune response, reproduction, and wound healing, among other functions.

Zinc deficiency may affect around 17 percent of the world’s population, most heavily impacting the developing world. One of the notable side effects of this deficiency may be hair loss. As a result, zinc supplements are often thought of as a potential hair loss treatment. But is there any science to back this up?

Read on as we explore:

• The potential causes of hair loss
• The effect that zinc may have on hair growth
• The benefits of zinc on your overall health

What Causes Hair Loss?

Hair loss is more commonly seen in men (known as male pattern baldness), however female pattern hair loss can also occur in some women. Anyone who has experienced hair loss may have tried any of the countless remedies out there to promote hair growth. 

So, what exactly can lead to unwanted hair loss? According to research, there are a number of factors that may be at play, such as:

There are a wide range of hair growth supplements that are marketed for people with thinning hair, such as biotin and collagen. But could nutritional factors such as the amount of zinc you consume play a role in healthy hair growth?

Let’s start by taking a look at the importance of zinc as part of a healthy diet.

Why We Need Zinc

Zinc is an essential micronutrient that plays a crucial role in enzymatic, structural, and regulatory functions in the body. In fact, over 50 different enzymes depend on zinc for their ability to properly do their job throughout the human body.

These enzymes participate in very important metabolic functions, including:

• Growth and development
• Skin health
• Immune system function
• Neurotransmission
• Vision
• Reproduction
• Intestinal ion transport
• Gene expression
• Wound healing
• Hair health

Zinc plays an antioxidant and anti-inflammatory role in the body, helping regulate oxidative stress and inflammatory cytokines in the body. It’s necessary for synaptic signaling in the brain, hormone release and regulation, and nerve transmission. 

The recommended daily value of zinc is:

• 8 milligrams per day for women
• 11 milligrams per day for men

Supplementing with Zinc for Hair Growth

So, why might zinc be connected to healthy hair? Some studies have shown that our hair follicles are closely intertwined with parts of the immune system that support healthy hair growth. As a result, a zinc deficiency is thought to be associated with hair loss. 

For this reason, zinc supplements have historically been recommended as a hair loss treatment. But is zinc actually effective? It turns out that’s still up for debate. 

In one 2005 study, researchers found that a high dose of zinc supplementation in mice inhibited and slowed the normal hair growth cycle. But, when taken for an extended period of time, zinc slows hair regrowth, so any potential positive effects may be dependent on the dose and the duration of administration. 

In another study, 15 alopecia patients with low serum zinc levels were given zinc supplements for 12 weeks. Out of the 15 patients, seven showed a marked recovery, meaning they experienced hair regrowth of more than 60 percent on their hair loss patch.

An interesting thing to note here is that the individuals being studied already had low zinc levels at the onset. This means that additional zinc may have been effective in as much as it corrected underlying deficiencies present. But what about if you’re already meeting your zinc needs? Is more zinc going to equal better hair growth? 

Many studies have explored the dose-dependent effect of nutrients, revealing the truth that more is not always better. Just as too little zinc may impair the immune system, too much zinc may do the same thing. And while too little zinc may negatively impact hair growth, some research also suggests that consuming excess zinc can lead to hair shedding or hair loss.

Whether zinc positively affects hair growth might depend on many factors, and more research is still needed to establish a direct link.

What To Know About Zinc Deficiency

Mild zinc deficiency affects about two billion people worldwide, mostly in developing countries. Because zinc is crucial for so many functions in the body, zinc deficiency can affect many different tissues and organs, including your: 

• Skin health
• Bone health
• Digestive system
• Reproductive system
• Immune system
• Central nervous system
  

Diarrhea and delayed growth can be a common sign of zinc deficiency in infants and children. Alopecia, delayed growth, and frequent infections may affect older children with zinc deficiency. In older adults, zinc deficiency can cause changes in cognitive and psychological function. 

If you are concerned about whether your diet includes enough zinc, consult your doctor and qualified nutrition professional for further guidance.

Who Is At Risk for Zinc Deficiency?

Dietary factors may lead to zinc deficiency. For example, because many types of meat and seafood have high levels of zinc, it has been thought that people on plant-based diets may be more at risk for zinc deficiency. 

Other groups who may be at a greater risk of zinc deficiency include:

• Premature and low-birth-weight infants
• Older breast-fed toddlers with inadequate intake of zinc-rich complementary foods
• Children and adolescents
• Pregnant and lactating (breast-feeding) women, especially adolescents
• People who receive intravenous feedings
• Malnourished individuals, including those with protein-energy malnutrition and anorexia nervosa
• Those with severe or persistent diarrhea or malabsorption 
• People with celiac disease or inflammatory bowel conditions
• Alcoholics and those with alcoholic liver disease
• Those with chronic kidney disease
• Those with sickle cell anemia
• Adults aged 65 years and older

Are Zinc Supplements Good to Take?

If you are considering increasing your zinc intake for any reason, it’s always a good idea to boost your whole food sources of zinc before considering supplements. The type of supplement is an important factor to consider too, as some types of zinc supplements may not be as well-absorbed by the body as others.

Keep in mind that you should always seek medical advice before adding any new supplements to your diet.

Zinc Supplements and Blood Sugar

You may also be wondering if zinc has any affect on your blood sugar. Interestingly, some meta-analyses have shown that zinc supplementation may reduce fasting glucose levels, postprandial glucose, and HbA1c levels in those with diabetes.

In these studies, zinc also appeared to reduce total cholesterol and triglycerides in both patients with and without diabetes. However, it’s important to note that these studies did not all control dietary zinc intake and they did not all account for possible current dietary deficiencies in zinc. 

Because of this, it’s possible that the benefit seen with supplementation could also be seen with an increase in zinc-rich foods. Research in this area is still lacking, and more is needed to determine zinc’s effect on blood sugar. 

Can You Take Too Much Zinc?

One of the reasons to check with your doctor before taking zinc supplements is the potential side effects. For example, some known side effects of zinc supplements may include abdominal pain, diarrhea, nausea, and even impaired immunity.

Another possible consequence of long-term consumption of large doses of zinc may be copper or magnesium deficiency. For this reason, the U.S. Food and Nutrition Board has set the tolerable upper intake level for adults at 40 milligrams per day, including both dietary and supplemental intakes of zinc. 

How to Add More Zinc to Your Diet

The Nutrisense dietitian team always recommends sourcing essential nutrients from whole food sources before supplementation when possible. If you’re looking to add more zinc to your diet, here are some zinc-rich foods may try adding into your diet:

• Oysters
• Beef
• Turkey
• Pork
• Shrimp
• Crab
• Sardines
• Pine nuts
• Soybeans
• Cashews
• Greek yogurt

Nutrients That May Interact With Zinc

If you are supplementing with zinc, there are a few potential interactions that zinc can have with other nutrients that you may want to keep in mind. Remember that before adding supplements you may want to consult your doctor or a registered dietitian for guidance.

Here are some of the nutrients that may interact with zinc:

Copper

Large doses of zinc (50 milligrams per day or more) over an extended period may interfere with the bioavailability of copper, another essential mineral that’s needed for many body processes. Smaller doses of zinc are not shown to affect copper absorption, and high copper intake does not affect zinc absorption. 

Iron

Iron and zinc both compete for absorption pathways. Dietary levels of iron don’t appear to affect zinc absorption, but high zinc supplementation may have a negative effect on iron levels.

Calcium

Calcium and zinc may have interactions in certain groups of people. For example, one study showed that increasing the calcium intake in the form of milk or calcium phosphate reduced zinc absorption and zinc balance in postmenopausal women.

Another study, however, found that increasing the calcium intake of adolescent girls in the form of calcium citrate malate, with a total calcium intake of 1,667 milligrams per day, did not affect zinc absorption or balance. The connection between zinc and calcium is still being investigated.

Folate or Folic Acid

The bioavailability of folate can be increased by the action of a zinc-dependent enzyme. Some studies show that folic acid supplementation may have a negative effect on zinc absorption in people with zinc deficiency.

Vitamin A

Zinc is a necessary component of a protein necessary for transporting vitamin A in the blood. For this reason, insufficient zinc may decrease vitamin A levels. 

Zinc deficiency has also been associated with a decreased release of vitamin A from the liver. This may contribute to the symptoms of night blindness that are seen with zinc deficiency.