Although we have long understood that reproduction is a nutrient-intensive process, modern science is just beginning to discover the ways in which specific nutrients impact fertility, pregnancy, and childhood health. Thankfully, our understanding of preconception nutrition is growing and we are able to provide better guidance to prospective parents on how to optimize nutrient intake to prepare for pregnancy. In this article, we’re going to discuss why zinc is so important for supporting both male and female fertility, preventing pregnancy complications, and growing a healthy baby.

What is Zinc?

Zinc is a trace mineral that is needed throughout the body in small amounts to support normal function of a variety of systems. We need zinc to help us with:

• Immune function and wound healing

• Protein synthesis

• Sense of taste and smell

• Digestive function

• DNA synthesis

• Tissue growth and maintenance

• Skin and eye health

• Reducing inflammation and oxidative stress

• Thyroid and sex hormone metabolism

• Prostate function in men

How Does Zinc Support Fertility and Pregnancy?

Female Fertility

Zinc has been shown to support egg cell maturation and development and deficiency is associated with impaired egg fertilization and embryo growth. New research shows that zinc is actually needed at a much earlier stage of egg development than previously thought and that even short periods of deficiency during preconception can negatively impact fertility months later! Studies also show that zinc plays a role in the production and metabolism of estrogen and progesterone, as well as the conversion of thyroid hormones. Balanced levels of these hormones are critical to fertility and pregnancy. As an anti-inflammatory and antioxidant nutrient, zinc helps prevent damage to egg cells from oxidative stress, which can support and improve fertility. 

Male Fertility

Zinc’s effect on male fertility is well-documented in the scientific literature. Zinc supports testosterone production and has been shown to influence sperm concentration, motility, and viability. Zinc also helps to stabilize DNA within sperm cells, protecting them from damage. Multiple studies have found lower levels of zinc in the seminal plasma of infertile men, showing a clear connection between deficiency and infertility. Zinc’s role as an antioxidant is just as important to male fertility as it is to female fertility and studies show that supplementing with antioxidants significantly improves pregnancy and live birth rates in couples dealing with male subfertility.

Pregnancy and Fetal Health

Zinc is very important to your baby’s development during pregnancy and deficiency is associated with fetal growth restriction (both low birth weight and small for gestational age) and increased risk of neural tube defects, miscarriage, stillbirth, and preterm delivery. Maternal zinc deficiency has also been linked to certain chronic illnesses in children, such as immune system problems, behavioral abnormalities, and blood pressure issues. Ensuring adequate intake of zinc during preconception and early pregnancy can help to prevent these complications and support your baby’s overall health.

What Are the Signs and Symptoms of Zinc Deficiency?

According to the World Health Organization, about one third of the world population is affected by zinc deficiency. Also, certain medical conditions, dietary habits, and lifestyle choices increase the risk of zinc deficiency, such as gastrointestinal problems, sickle cell anemia, heavy alcohol consumption, smoking, hormonal contraceptive use, and eating a plant-based diet. Signs of deficiency include: 

• Recurrent infections

• Slow wound healing

• Changes in taste or smell

• Unexplained weight loss

• Diarrhea or other digestive problems

• White spots on fingernails

• Loss of appetite

• Hormonal imbalances

• Hair loss

• Brain fog or memory issues

• Skin problems

Where Do We Get Zinc?

Diet

About half of the zinc in the American diet comes from animal foods and about one quarter comes from beef consumption alone. Zinc can also be found in high concentrations in certain plant foods, like legumes, nuts, seeds, and whole grains. However, these foods are also high in substances that inhibit zinc absorption (like phytic acid) and studies have raised concerns over the bioavailability of zinc from plant foods. You can increase zinc absorption from these foods by using special preparation techniques like soaking, sprouting, or fermenting. On the other hand, zinc absorption has actually been found to be enhanced by the consumption of animal foods. Overall, the top food sources of zinc are:

• Shellfish – especially oysters

• Red meat

• Poultry and eggs

• Dairy products

• Legumes – chickpeas, lentils

• Seeds – pumpkin, hemp, sesame

• Nuts – cashews, pine nuts, pecans

• Whole grains – quinoa, rice, oats

Supplements

We can also obtain zinc from supplements and most prenatal vitamins, multivitamins, and antioxidant formulas contain zinc. Some people may need to supplement with additional zinc, especially in cases of significant deficiency. However, because zinc operates in a delicate balance with other minerals in the body (such as copper), you should consult with a qualified practitioner prior taking a standalone zinc supplement. There are several forms of zinc available in supplements, including:

• Zinc sulfate

• Zinc acetate

• Zinc citrate

• Zinc gluconate

• Zinc picolinate

Research suggests that zinc picolinate may be easier to absorb than other forms of zinc but the citrate and gluconate are fairly common in supplements and appear to be effective. It is possible to take too much zinc, which may result in gastrointestinal pain/upset, headaches, and signs of mineral imbalance. 

How Much Zinc Do We Need? 

The RDA for zinc is 8mg for adult women and 11mg for adult men. During pregnancy, the RDA increases to 11mg for women. Food is definitely the safest way to consume zinc and, ideally, you would be able to easily meet your requirements through diet. However, if you are trying to consume most of your zinc from plant foods, you have digestive problems, or you are showing signs of deficiency, you likely need to consume much more than the RDA to support optimal fertility and a healthy pregnancy. 

Although supplementing is an option, you should be cautious and work with a qualified practitioner who can help you determine your individual needs and assist with any underlying issues that may impact your ability to absorb and utilize zinc. Taking zinc as part of a prenatal or multivitamin is likely safe, since those supplements contain other nutrients that work synergistically with zinc in the body. Just be sure not to supplement above 30-40mg per day for an extended period of time, as this may lead to mineral imbalances and other problems.