The Many Roles of Zinc
In 1958, Dr. Ananda Prasad had a 21-year-old patient from an Iranian village who presented as a prepubescent boy with underdeveloped sex organs and an absence of body hair. By 1963 his team discovered this was, in large part, due to a zinc deficiency. This prompted the first recommended daily intake (RDA) for zinc about a decade later.
Since then, we have discovered the numerous jobs zinc does for our bodies. It assists vitamin A and D as well as a number of hormones (sex, stress and thyroid) to do their jobs. Zinc activates many enzymes which in turn offer antioxidant protection and immune support. Zinc is necessary for the production of nitric oxide which keeps our blood pressure in check. It is also vital for the construction of all proteins. This is huge since everything in our body is either made by proteins or are proteins. For example, proteins are needed to bind and remove heavy metals from the body.
How Much Do We Need?
Health Canada sets the Recommended Dietary Intake (RDI) at 9 mg/day for adult males and 8 mg/day for adult females. These amounts are deemed sufficient to prevent deficiencies in most healthy adult individuals. However, the lack of sensitive indicators of zinc nutritional status in humans makes it difficult to determine the intake level of zinc most likely to promote optimal health. Some experts argue that certain individuals, such as a bodybuilder or someone on a strict vegan diet would not thrive on these levels.
Who Might Be Deficient?
The World Health Organization (WHO) estimates that half the world’s population is at risk of zinc deficiency. The first sign of mild zinc deficiency is usually dry skin patches. The classic symptoms of zinc deficiency are dry skin, severe acne, sore throat and diarrhea (secondary to infection). These symptoms are related to zinc’s important role in healthy skin and immunity. While zinc levels can be measured by a blood test, current methods are too crude to pick up marginal deficiencies. The following populations and disease states may put people at higher risk for deficiencies because of reduced dietary intake, absorption, retention or loss, and/or increased need:
- Digestive Disorders (Crohn’s, Celiac, Short Bowel Syndrome)
- Persistent vomiting or diarrhea
- Imbalanced and processed diets (ex. excessive sugar, fat or alcohol)
- Other (impaired methylation, rare genetic defects, etc.
Diet Is the Key
The most common reason for zinc deficiency is an imbalanced diet. The best sources of zinc are animal products (cheese excluded) especially oysters, red meat and organ meats. For many reasons (environmental, health and animal welfare), people opt for a plant-based diet. Vegetarian and vegan diets are high in phytates which are nutrient blockers that make minerals like zinc harder to absorb. A well planned and executed non-processed and balanced plant-based diet should provide enough zinc, in theory. Soaking, sprouting and fermenting of nuts, seeds and grain can help reduce the phytate content.
Studies on Zinc
Many clinical trials have proved that zinc supplements have the potential to aid with different illnesses, especially those caused by or worsened by a deficiency. Here are a few of the clinically validated uses for zinc supplementation:
- Zinc deficiency
- Treatment-resistant depression
- Skin (acne, wound healing, psoriasis)
- Type II Diabetes
- Delayed progression of age-related macular degeneration (AMD)
About Zinc Picolinate
Zinc supplements come in many forms. Zinc Picolinate is thought to be one of the most bioavailable forms, in contrast to poorly absorbed forms such as zinc oxide. Zinc Picolinate is zinc that is bound to an organic acid called picolinic acid. This complex facilitates the passage of zinc through the gastrointestinal wall and into the circulatory system so that it can be readily transported and utilized by the body. Many complimentary healthcare providers prefer this form.
Caution: Taking large quantities of zinc (50 mg/day or more) over a period of weeks can interfere with copper bioavailability. If taking high doses of zinc for prolonged periods it is considered best practices to maintaining a zinc-to-copper ratio between 15-to-1 and 2-to-1.
By Thalia Charney, MA, Holistic Nutrition and Wellness Coach