Forms of zinc – which zinc supplement to choose?

Zinc is an element essential for the proper functioning of the body, there is no doubt about it. Of course, its best source is a balanced diet, but when the body starts to show signs of its deficiency, it can also be supplemented through supplementation. However, on product labels, zinc appears in several forms – which one is best to choose? We check this in this article.

What forms of zinc are found in supplements?

The effectiveness of a zinc supplement is influenced by two aspects that we can verify from the product label: the concentration and the type of active substance. According to nutritional standards, the daily requirement for zinc ranges from 8 to 13 mg/day depending on age (lower intake for children aged 10-13), sex (higher for men), and body condition (higher for athletes, but also pregnant and breastfeeding women) ¹. For this reason, supplementation doses should also range from 10 to 15 mg. Zinc is one of the elements where both deficiency and excess cause negative effects on the body’s health, which is why in the case of supplements with higher doses, it is better to consult a doctor who will confirm the need for their use.

As for the form of zinc, in supplements we can find several zinc compounds with other substances that can stabilize zinc or increase its bioavailability. On a side note – zinc contained in food is absorbed at a level of about 40%, although this number increases in situations of mineral deficiency. In the case of supplements, bioavailability is significantly higher – this also speaks in favor of supplementing with products with smaller doses of zinc, but offered in highly bioavailable forms. The most popular include:

Zinc Citrate

This is zinc combined with citric acid, which, like some amino acids, increases its bioavailability for the body.

Zinc Picolinate

A combination of zinc with picolinic acid, which also facilitates the absorption of minerals; picolinic acid does not disrupt stomach function, making it a good choice for people struggling with digestive problems.

Zinc Gluconate

A form present, for example, in BestProtect. It is an organic zinc salt of gluconic acid; its origin makes it both highly absorbable and well-tolerated by sensitive digestive systems. It also does not lose its properties during longer storage, which allows it to be used in supplements sold in larger packages. In the case of BestProtect, gluconate has been additionally combined with l-lysine, an amino acid that facilitates the body’s absorption of zinc.

Zinc Amino Acid Chelate

This is an interesting and still highly bioavailable form of zinc, in which amino acid molecules have undergone chelation, i.e., given an electrical charge – this attracts zinc molecules, increasing their density. For the body, this means that every microgram of this compound that reaches the intestine delivers slightly more zinc than its other forms.

Zinc Oxide – is it effective?

The only inorganic form of zinc found in supplements is ZnO, i.e., zinc oxide. It is a widely used stabilizing, fixing, and preserving agent in various industries. Due to its antibacterial properties, it is an effective ingredient in ointments and products intended to support healing processes and limit the growth of microorganisms (e.g., in topical ointments, anti-acne creams, mouthwashes, etc.). Although it is added to food products (and, interestingly, their packaging), these are rather actions aimed at utilizing its properties to protect food from spoilage. In comparative studies, zinc oxide was rated as less absorbable than zinc gluconate and zinc citrate in adults ², although these studies did not concern this compound in the form of nanoparticles. These, in turn, are still being investigated in the context of a nutritional additive, but… for livestock³. For this reason, in dietary supplements, it is better to look for zinc compounds with chelated amino acids or acids such as citric, gluconic, or picolinic acid.

Which form of zinc is best absorbed?

Precisely determining the bioavailability of individual zinc compounds is difficult due to the different criteria adopted during studies to determine the effectiveness of a given substance. Current knowledge about differences in absorbability can be summarized in the form of several statements:

• zinc amino acid chelates, due to their structure, deliver the highest concentration of zinc to the body per mg of substance,
• zinc combined with acids: citric, gluconic, and picolinic showed comparable absorbability,
• as a supplement, zinc oxide (ZnO) showed the worst absorbability, however, it is a substance with high antibacterial potential when applied topically.

What to pay attention to when choosing the form?

Key to choosing a supplement should be not only the form of zinc administered, but its concentration, as well as the individuals supplementing it. For example, from the perspective of pure efficiency in replenishing zinc deficiencies, amino acid chelate would be the best choice, as it delivers the largest amount of the element per weight of active substance. However, the body of a person suffering from digestive system diseases may not be able to absorb it. In such a situation, zinc gluconate or citrate may show better effectiveness in replenishing deficiencies due to the very fact of higher tolerance by the body of the person taking the supplement.

How to match the form of zinc to your needs?

Zinc can be an element of both supplementation and topically applied products. The form of zinc and the way it is used should be adjusted depending on what benefits the addition of zinc is expected to bring.

Zinc for acne

Thanks to its antibacterial and skin regeneration-supporting properties, zinc is one of the active ingredients worth looking for in anti-acne ointments. In this form, it can appear both as an oxide and as zinc gluconate. Such an ointment creates a natural barrier against microorganisms, protecting the skin and improving the effectiveness of its healing.

Zinc for immunity

The cold season, but also a general feeling of weakness and drowsiness, is a signal to start zinc supplementation – even if only to enable the body to properly synthesize enzymes and proteins responsible for the effective functioning of the immune system.

Since the body’s immunity largely depends on the health of the digestive system, when supplementing zinc to support health, it is worth using highly absorbable and well-tolerated forms of zinc by the stomach and intestines, such as zinc citrate and gluconate, with additions facilitating its absorption, such as l-lysine in BestProtect.

Importantly, a form better tolerated by the digestive system may also be a more beneficial supplementation for pregnant women, especially those whose hormonal changes manifest as nausea, loss of appetite, and other gastric ailments.

Zinc for athletes

Increased physical activity – both as part of heavy work and in sports – is associated with a naturally increased demand for zinc. In this situation, in addition to increasing its intake in the diet, it is worth introducing supplementation. In the case of a body that does not show digestive system problems, it is possible to use zinc amino acid chelate supplements, however, introducing supplementation with highly absorbable forms of zinc in amounts slightly exceeding the recommended average daily intake should also bring positive effects.

Bibliography:

• Chruściel P., Kubasińska-Sajnóg A., Characteristics and application of zinc in cosmetology and dietetics, Aesthetic Cosmetology and Medicine, vol. 10, no. 4/2021.
• Szcześniak M., Grimling B., Meler J., Zinc – the element of health, Farmacja Polska, vol. 70, no. 7/2014.
• M. Jarosz, E.Rychlik et al., Nutritional norms for the population in Poland and their application, National Institute of Public Health, 2020.
• Wegmuller R., Tay F., Zeder C., Brnic M., Hurrell R.F. Zinc absorption by young adults from supplemental zinc citrate is comparable with that from zinc gluconate and higher than from zinc oxide Journal of Nutrition, no. 144/2014, issue 2;