Zinc Citrate Absorption Superior to Oxide

According to new research published online in The Journal of Nutrition*, zinc citrate showed superior absorption compared to zinc oxide and was on pair with the nutritional benchmark zinc gluconate.

Despite of the benefits of zinc citrate over soluble zinc salts concerning zinc content and more neutral taste, no human absorption data was available to date.

The randomized, double-blind, three-way cross-over study was lead by Rita Wegmüller and Richard Hurrel of the ETH Zurich. 15 healthy young adults received 10mg of elemental zinc as a supplement without food via zinc citrate, zinc gluconate or oxide zinc and absorption was measured using the double isotope tracer methodology.

Median fractional absorption of zinc from zinc citrate was 61.3% and was not different to that from zinc gluconate with 60.9%, but absorption from zinc oxide was at 49.9% significantly lower than from both other supplements (P < 0.01).

Interestingly, three subjects had little or no absorption from zinc oxide. This might be explained by the fact that zinc oxide is an insoluble compound which may not be dissolved sufficiently by people with low gastric acid production.

The authors conclude that “…zinc citrate could be a useful compound for zinc supplementation. At the present time, WHO recommends the use of the water soluble compounds zinc sulfate, zinc acetate or zinc gluconate in the form of syrups or dispersible tablets in the management of diarrhea. Zinc citrate might be a useful addition to this list and be especially suitable for chewable/crushable tablets since it has better sensory properties…”

Types of Zinc Supplements

When choosing a zinc supplement, you’ll likely notice that there are many different types available.

These various forms of zinc impact health in distinct ways.

Here are a few you might find on the market:

• Zinc gluconate: As one of the most common over-the-counter forms of zinc, zinc gluconate is often used in cold remedies, such as lozenges and nasal sprays.
• Zinc acetate: Like zinc gluconate, zinc acetate is often added to cold lozenges to reduce symptoms and speed up the rate of recovery.
• Zinc sulfate: In addition to helping prevent zinc deficiency, zinc sulfate has been shown to reduce the severity of acne.
• Zinc picolinate: Some research suggests that your body may absorb this form better than other types of zinc, including zinc gluconate and zinc citrate.
• Zinc orotate: This form is bound to orotic acid and one of the most common types of zinc supplements on the market.
• Zinc citrate: One study showed that this type of zinc supplement is as well-absorbed as zinc gluconate but has a less bitter, more appealing taste.