Zinc supplementation

Trace elements are essential cofactors for numerous biochemical processes. Trace elements that are added routinely to PN include zinc, selenium, copper, manganese, and chromium. There are various commercial parenteral trace element formulations that can be added to PN admixtures (e.g., MTE-5 ). Zinc is important for wound healing, and patients with high-output fistulas, diarrhea, burns, and large open wounds may require additional zinc supplementation. Patients may lose as much as 12 to 17 mg zinc per liter of gastrointestinal (GI) output (e.g., from diarrhea or enterocutaneous fistula losses) however, others have demonstrated that 12 mg/day may be adequate to maintain these patients in positive zinc balance.18 Patients with chronic diarrhea, malabsorption, and short-gut syndrome may have increased selenium losses and may require additional selenium supplementation. Patients with severe cholestasis should have copper and manganese... 

While it seems that there is little interference between iron and zinc metabolism under normal dietary situations, the possibility of interference must be taken into account when considering iron or zinc supplementation in developing countries. 

Humans given zinc supplements should be aware of possible complications (Fosmire 1990). Low intakes of 100 to 300 mg of zinc daily in excess of the recommended dietary allowance of 15 mg Zn daily may produce induced copper deficiency, impaired immune function, and disrupted blood lipid profiles. Patients treated with zinc supplements (150 mg daily) to control sickle cell anemia and nonresponsive celiac disease developed a severe copper deficiency in 13 to 23 months normal copper status was restored by cessation of zinc supplements and increased dietary copper (Fosmire 1990). 

Zinc, A great deal of Information Is available on the effect of calcium on zinc metabolism, particularly In animals (30,31), but only a few studies have been carried out In man (32,33), On the other hand, to our knowledge, no studies have been reported on the effect of zinc on calcium metabolism In man. In studies carried out In this Research Unit, It has been demonstrated that large amounts of zinc significantly decrease the Intestinal absorption of calcium If the zinc supplements are given during a low calcium Intake (34),... 

Table I shows that the addition of 140 mg of zinc as zinc sulfate per day, during a low calcium Intake of 230 mg/day, decreased the urinary calcium, Increased the fecal calcium and the calcium balance remained unchanged. In nine patients studied during a low calcium Intake, the Intestinal absorption of calcium decreased significantly during the high zinc Intake, the absorption values averaging 61 + 6,6% In the control study and 39 + 4,6% during zinc supplementation, However, the decrease In calcium absorption was abolished...

All of the studies were conducted with weanling, male albino rats of the Sprague-Dawley strain (Holtzman company). The basal diet used for these studies consisted of casein, starch, vegetable oil, vitamin and mineral mixtures, and cellulose. The Wesson Modification of the Osborne-Mendel mineral mixture was used in all studies. This mineral mixture contained no zinc, but it was adequate in the other minerals required by the rat. Most of the non-zinc-supplemented diets used in the various experiments contained approximately 7 ppm zinc. The level of mineral mixture used in the basal diets was 4%, and based on the chemical composition of the mixture, the basal diets contained approximately 0.57% calcium and 0.41% phosphorus ... 

Table III. Effects of Calcium, Phosphorus, and Zinc Supplements on Growth and Bone Mineralization of Young Rats...

Hydrox5rpyranonate and hydroxypyridinonate complexes have been patented for the treatment of zinc deficiency (451) and are used in zinc supplements. Maltolate and ethylmaltolate complexes of zinc, copper, and tin have been included as essential constituents in patents for formulations for oral care (96). The arylmercury(II) complexes RHgL, where R = 4-XCgH4, X — Me, OMe, NO2, and L — malt, koj, have been tested for antibacterial activity (101). 

The effects of leucaena and mimosine on nonruminants can be reduced to some extent by diet supplementation with ferrous sulfates. Mimosine forms a complex with iron, which is excreted in the feces. Zinc supplementation has reduced the toxicity in cattle and it is believed that copper and zinc ions bind more strongly to mimosine than most other amino acids. 

A deficienqf of zinc in humans will retard growth, both physically and mentally, and contribute to anemia. It is present in many foods, particularly proteins (meat). A balanced diet provides an adequate amount of zinc. Not more than 50 milligrams per day of dietary zinc supplement should be taken, given that high levels of zinc in the body are toxic. Human bodies contain about two grams of zinc. A deficiency of zinc can cause a lack of taste and can delay growth as well as cause retardation in children. 

Lind, T., Lonnerdal, B., Stenlund, H., Gamayanti, I. L., Ismail, D., Seswandhana, R., and Persson, L. A. (2004). A community-based randomized controlled trial of iron and zinc supplementation in Indonesian infants Effects on growth and development. Am. ]. Clin. Nutr. 80, 729-736. 

Both transient and persistent hair loss have been associated with valproate use. Patients with valproate-induced alopecia may benefit from zinc supplementation, at a dose of 22.5 mg/day (Hurd et al. 1984). 

Additional studies have further supported a role for zinc in the etiology of cancer of the esophagus (24,25). In the presence of a zinc deficit, the precursors of methylbenzylnitrosamine (MBN) more readily induced both esophageal and forestomach tumors in rats, compared to zinc-supplemented control rats. Table VII illustrates these effects. 

Oishi S, Hiraga K. 1983. Testicular atrophy induced by di(2-ethylhexyl)phthalate Effect of zinc supplement. Toxicol Appl Pharmacol 70 43-48. 

Supplementation of cows diets with zinc has been found to reduce spontaneous lipolysis significantly (Hermansen et al., 1995). The authors suggested that zinc deficiency may be a potential risk factor for spontaneous lipolysis. However, corroborative evidence is required before zinc supplementation could be recommended for reducing spontaneous lipolysis. 

Fll. Franceschi, C., Chiricolo, M., Licastro, F., Zannotti, M., Masi, M., et al., Oral zinc supplementation in Down s syndrome Restoration of thymic endocrine activity and of some immune defects. J. Ment. Defic. Res. 32, 169-181 (1988). 

In this study we have shown that even a mild deficiency of zinc can adversely Influence testicular function in adult subjects, which was reversible with zinc supplementation. 

The first pair of subjects (Patients 1 and 2) received hospital diet for 2 weeks then they received the experimental diet with 10 mg of supplemental zinc (as zinc acetate) daily orally for 6 weeks. After this, they were given only experimental diet (daily zinc Intake of 2.7 mg) for 24 weeks. At the end of this phase, while continuing the experimental diet, the two subjects received 30 mg of zinc supplement (as zinc acetate) daily orally for 12 weeks. Finally, these subjects were maintained on hospital diet with total dally Intake of 10 mg zinc plus 30 mg of oral zinc supplement (as zinc acetate) for 8 weeks. The hospital diet provided the same amount of calories and protein as the experimental diet. Thus, these two subjects were observed for a total period of 52 weeks. 

The second two subjects (Patients 3 and 4) received hospital diet (10 mg of zinc intake daily) for 3 weeks, followed by the experimental diet with 30 mg of oral zinc supplement (as zinc acetate) for 5 weeks. After this, they were given only experi-... 

In the first two subjects (Patients 1 and 2), who received 2.7 mg of zinc daily, the weight loss was more pronounced in comparison with the second pair of subjects (Patients 3 and A), who received 3.5 mg of zinc dally. After repletion with zinc, the weight stabilized in three out of four subjects and in one subject (Patient 1), although the weight loss continued during the zinc-supplemented period, the rate of weight loss as determined by the slope of the curve was decreased. 

Plasma alkaline phosphatase was monitored carefully In the second group of subjects. In both cases, the activity slowly declined as a result of zinc restriction, and after supplementation with zinc, the activity nearly doubled In 8 weeks. In all four subjects, the activity of plasma rlbonuclease was almost twice as great during the zlnc-restrlcted period as In the zinc-supplemented phase. Plasma lactic dehydrogenase activity de-... 

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