Maternal Milk Concentration of Zinc, Iron, Selenium, and Iodine and Its Relationship to Dietary
Intakes
Hannon MA, et al.
Biol Trace Elem Res (2009) 127:6-15.
The dietary intake of zinc (Zn), Iron (Fe), selenium (Se), and iodine (I) of 31 lactating Mexican-American women attending the Hidalgo
County WIC program in Rio Grande Valley (RGV), Texas was estimated from 24-h dietary recall interviews. Milk samples were
obtained from lactating mothers who had infants 3 months of age and younger. Milk samples were collected in two visits to assess change
in breast milk composition after 1-3 months postpartum: group A – after 30-45 days and group B – 75-90 days. Dietary intakes indicated
that the study participants had significantly inadequate percent energy intakes than the DRI (Dietary Recommended Intakes) percent
recommended kilocalorie values but protein intakes were substantially higher than the percent recommended values. The estimated
percent Zn, Fe, Se, and I intakes were also significantly lower than the DRI percent recommended values. The lactating mothers
consumed significantly less Zn, Se, and I when compared to the Recommended Dietary Allowances (RDA) even though Fe intake was
higher than the RDA value. Breast milk concentration of Zn, Fe, and Se were in agreement within the range of representative values for Constituents of Human Milk but I has significantly less concentration than the representative value. There was no statistically significant
correlation observed between dietary intake and milk concentration of Zn, Fe, Se, and I. This study compares the estimated dietary
intake of zinc, iron, selenium and iodine to the concentration of these trace elements in the maternal milk of lactating women of
Mexican-American heritage who attend the Rio Grande Valley WIC clinic.
Restoring the Metabolic Disturbance of Zinc: May Not Only Contribute to the Prevention of
Esophageal Squamous Cell Cancer
Guo W, et al.
Med Hypotheses, 2008 Dec; 71(6):957-9.
The relationship between zinc deficiency (ZD) and esophageal squamous cell cancer (ESCC) is well-established. Zinc supplement has
long been considered as potential strategy for prevention of ESCC. However, the effect of zinc replenishment on prevention of ESCC is
still in controversy and no convincing evidence to support these proposals has become known. We hypothesized that zinc deficiency
might be the major initiator for dysfunction of numerous genes and subsequent carcinogenesis of esophagus and replenishment to of zinc
might improve the prognosis of patients with ESCC.
Recommended Nutritional Supplements for Bariatric Surgery Patients
Malone M.
Ann Pharmacother, 2008 Dec; 42(12):1851-8.
To review nutritional supplements commonly required after bariatric surgery to provide a practical guide and reference source for
generalist healthcare providers. A PubMed literature search (1988-July 2008) was conducted, using the search term nutritional deficiency
after bariatric surgery, and was limited to English-language literature on adult (aged >19 y) human subjects. Additional references from
the selected literature were also included. Data were extracted from large clinical series and practice guidelines whenever possible. Case
reports were used only when they were the sole information source. Nutritional deficiencies that occur after bariatric surgery depend
significantly on the type of surgery performed. Restrictive procedures such as gastric banding are the least likely to cause nutritional
deficits, since none of the intestine is bypassed. Malabsorptive procedures such as biliopancreatic diversion or mixed
restrictive/malabsorptive procedures (eg, Roux-en-Y gastric bypass) can result in serious nutritional problems when patients do not take
required supplements after surgery. Vitamins and minerals that are commonly deficient in this circumstance include vitamin B12, calcium,
vitamin D, thiamine, folic acid, iron, zinc, and magnesium. Rare ocular complications have been reported with hypovitaminosis A.
Healthcare professionals, especially those who practice outside large bariatric centers, must be aware of the supplements required by
patients who have had bariatric surgery. Many patients fail to follow up with the surgery centers and are managed by their primary care
teams and community pharmacists, especially in the selection of multivitamin and nutritional supplements.
Serum Testosterone and Urinary Excretion of Steroid Hormone Metabolites After
Administration of a High-dose Zinc Supplement.
Koehler K, et al.
Eur J Clin Nutr, 2009 Jan; 63(1):65-70.
To investigate whether the administration of the zinc-containing nutrition supplement ZMA causes an increase of serum testosterone
levels, which is an often claimed effect in advertising for such products; to monitor the urinary excretion of testosterone and selected
steroid hormone metabolites to detect potential changes in the excretion patterns of ZMA user. Fourteen healthy, regularly exercising
men aged 22-33 years with a baseline zinc intake between 11.0 and 23.2 mg day (-1) prior to the study. Supplementation of ZMA
significantly increase serum zinc (P=0.031 and urinary zinc excretion (P=0.035). Urinary pH (P=0.011) and urine flow (P=0.045)
were also elevated in the subjects using ZMA. No significant changes in serum total and serum free testosterone were observed in
response to ZMA use. Also, the urinary excretion pattern of testosterone metabolites was not significantly altered in ZMA users. The
present data suggest that the use of ZMA has no significant effects regarding serum testosterone levels and the metabolism of testosterone
in subjects who consume a zinc sufficient diet..
Selenoproteins
Lu J, et al.
J Biol Chem, 2009 Jan 9;284(2):723-7.
Selenium is an essential micronutrient for man and animals. The role of selenium has been attributed largely to its presence in
selenoproteins as the 21st amino acid, selenocysteine (Sec, U). Sec is encoded by TGA in DNA. A unique mechanism is used to decode
the UGA condon in mRNA to co-translationally incorporate Sec into the growing polypeptide because there is no free pool of Sec. In the
human genome, 25 genes for selenoproteins have been identified. Selenoproteins such as glutathione peroxidases, thioredoxin
reductases, and iodothyronine deiodinases are involved in redox reactions, and Sec is an active-site residue essential for catalytic activity.
Selenoproteins have biological functions in oxidoreductions, redox signaling, antioxidant defense, thyroid hormone metabolism, and
immune responses. They thus possess a strong correlation with human diseases such as cancer, Keshan disease, virus infections, male
infertility, and abnormalities in immune responses and thyroid hormone function.
Vanadium Treatment of Type 2 Diabetes: A View to the Future
Thompson KH, et al.
J Inorg Biochem, 2008 Dec 24.
3-Hydroxy-2methyl-4pyrone and 2-ethyl-3hydroxy-4pyrone (maltol and ethyl maltol, respectively) have proven especially suitable as
ligands for vanadyl ions in potential insulin enhancing agents for diabetes mellitus. Both bis(maltolato) oxovanadium(IV)(BMOV), and
the ethylmaltol analog, bis(ethylmaltolato) oxovanadium (IV) (BEOV), have the desired intermediate stability for pro-drug use, and have
undergone extensive pre-clinical testing for safety and efficacy. Pharmacokinetic evaluation indicates a pattern of biodistribution
consistent with fairly rapid dissociation and uptake, binding to serum transferrin for systemic circulation and transport to tissues, with
preferential uptake in bone. These bis-ligand oxovanadium(IV) (VOL(2)) compounds have clear advantage over inorganic vanadyl sulfate
in terms of bioavailability and pharmaceutical efficacy. BEOV has now completed Phase I and has advanced to Phase II clinical trials. In
the phase I trial, a range of doses from 10 mg to 90 mg BEOV, given orally to non-diabetic volunteers, resulted in no adverse effects; all
biochemical parameters remained within normal limits. In the Phase IIa trial, BEOV (AKP-020), 20 mg, daily for 28 days, per os, in
seven type 2 diabetic subjects, was associated with reductions in fasting blood glucose and %HbA1c; improved responses to oral glucose
tolerance testing, versus the observed worsening of diabetic symptoms in the two placebo controls.
|
|
