As with all supplements, whether they be vitamins or minerals, quality and format are vital. Our bodies only recognise natural forms of nutrients – synthetic, inexpensive forms cannot be used. Many over-the-counter supplements are synthetic and, therefore, a waste of money. Furthermore, it is important to always be assessed for nutritional deficiencies to ensure you give your body what it needs and don’t upset the delicate balance of minerals by taking too much of one to the detriment of another.
Zinc is a mineral and essential to good health. It is not only a cofactor in over 200 enzymatic reactions within the body, but also an important component of the antioxidant superoxide dismutase and, therefore, may assist in protecting the body from free radical damage.
Zinc has an essential role in DNA, RNA and protein synthesis. It also assists the body to metabolise proteins carbohydrates and fats.
Zinc has a vital role in the maturation of sperm, ovulation, fertilisation, and the metabolism of reproductive hormones. It is essential to maintaining healthy vision, nervous system function and bone health. It is pivotal for the healthy functioning of the immune system, supporting the healing of minor wounds and helping to maintain the health of the skin. Zinc is also of fundamental importance for proper growth and development as well as playing an essential part in maintaining the structure and integrity of cellular membranes.
Preclinical trials show zinc glycinate supplementation may provide more efficient absorption compared to inorganic sources of zinc, as measured by the post-supplementation expression of various zinc-transporters. (1)
Pyridoxal 5-phosphate (P5P) is the metabolically active form of Vitamin B6 in the body. In this formula, it acts as a zinc synergist playing a role in the metabolism of carbohydrates, proteins, and fats and in DNA synthesis. Alongside zinc, P5P has an integral role in maintaining a healthy immune system. The amino acid methionine also acts a zinc synergist due to its favourable effect of improving zinc absorption. (2,3)
Zinc deficiency is more common than we may think.
Zinc and the common cold
Zinc plays an important role in maintaining healthy immune function. Zinc deficiencies have been associated with impaired immunity through insufficient natural killer cell and interleukin-2 production. Zinc also has specific actions in upper respiratory infections inhibiting rhinovirus replication and helping mitigate susceptibility to airways damage in the presence of serious respiratory infection.
Previous studies have not been conducted examining the effect of chelated zinc supplementation in preventing common cold in children. In this study the researchers reasoned that because chelated forms of zinc are better absorbed and more easily digested compared with ionic forms, then utilising a chelated form may produce more efficacious results.
They conducted a double blind randomised placebo controlled trial researchers seeking to investigate the effect of three months’ oral zinc supplementation on symptoms of the common cold in 8-13 year old school students. 100 healthy school children were randomly assigned to receive either 15 mg tablet of zinc bis-glycinate once a day or an identical sham. All the investigators, parents, and students were blinded as to group assignment.
At baseline the groups were equal with regard to gender distribution and body mass was similar although the intervention group tended to have a lower body mass index, be somewhat shorter in stature and younger. At study close the intervention group had no fewer incidences of contraction of the common cold; however the duration of symptoms was considerably shorter in the intervention group.
The children receiving the daily zinc had significantly fewer days with two or more symptoms. Coughs lasted 1 day compared to 6 days in the placebo group, P < 0.01 and rhinorrhoea symptoms persisted for 2 days compared to 5.5 days in the placebo P < 0.01.
Although chelated zinc did not reduce the incidence of common cold, it provides promising evidence that a daily dose of 15 mg of chelated zinc over three months may be effective in dramatically reducing the duration of common cold symptoms.(4)
References:
- Huang D, Zhuo Z, Fang S, Yue M, Feng J. Different zinc sources have diverse impacts on gene expression of zinc absorption related transporters in intestinal porcine epithelial cells. Biological trace element research. 2016 Oct 1;173(2):325-32.
- Lönnerdal BO. Dietary factors influencing zinc absorption. The Journal of nutrition. 2000 May 1;130(5):1378S-83S.
- House WA, Van Campen DR, Welch RM. Influence of dietary sulfur-containing amino acids on the bioavailability to rats of zinc in corn kernels. Nutrition Research.1996 Feb 1;16(2):225-35.
- Rerksuppaphol S, Rerksuppaphol L. A randomized controlled trial of chelated zinc for prevention of the common cold in Thai school children. Paediatrics and international child health. 2013 Aug 1;33(3):145-50.