Science Based Nutrition

May 20, 2009

[Vitamins, minerals, and phytochemicals] Regular consumption of a complementary food fortified with ascorbic acid and ferrous fumarate or ferric pyrophosphate is as useful as ferrous sulfate in maintaining hemoglobin concentrations >105 g/L in young Bangladeshi children

Background: Non-water-soluble iron compounds have been reported to be less well absorbed than ferrous sulfate in young children, and concern has been raised about their usefulness as food fortificants.

Objective: The objective was to evaluate the usefulness of ferrous fumarate and ferric pyrophosphate, compared with ferrous sulfate, in maintaining hemoglobin concentrations >105 g/L in Bangladeshi children.

Design: Two hundred thirty-five children aged 7–24 mo (hemoglobin >105 g/L) were randomly assigned in a double-blind study to receive an infant cereal fortified with ferrous fumarate, ferric pyrophosphate, or ferrous sulfate. One serving of cereal (9.3 mg Fe; molar ratio of ascorbic acid to iron of 3:1) was consumed per day, 6 d/wk, for 9 mo. Blood samples were drawn at 4.5 and 9 mo.

Results: Raw data were reformatted, and a "time to event" was calculated that corresponded to reaching the following thresholds: hemoglobin <105 g/L, plasma ferritin <12 µg/L, or plasma C-reactive protein >10 mg/L at baseline, 4.5 mo, or 9 mo. Data were censored when children did not reach the threshold or were lost to follow-up. A Kaplan-Meier approach was used to compare the 3 groups. No statistically significant differences were observed for hemoglobin <105 g/L (P = 0.943), plasma ferritin <12 µg/L (P = 0.601), or plasma C-reactive protein >10 mg/L (P = 0.508).

Conclusions: Contrary to earlier concerns, these results do not indicate differences in usefulness between water-soluble and non-water-soluble iron compounds in maintaining hemoglobin concentrations and preventing iron deficiency. These data will be important in the development of food-fortification strategies to combat anemia and iron deficiency in highly vulnerable population groups.

September 1, 1976

Ineffectiveness of human chorionic gonadotropin in weight reduction: a double-blind study

Filed under: Main Content — Tags: , , , , , , , , , — MR Stein, RE Julis, CC Peck, W Hinshaw, JE Sawicki, JJ Deller Jr @ 2:00 am
MR Stein, RE Julis, CC Peck, W Hinshaw, JE Sawicki, JJ Deller Jr
Sep 1, 1976; 29:940-948
ORIGINAL RESEARCH COMMUNICATIONS

February 7, 2012

[Vitamins, minerals, and phytochemicals] Vitamin D supplementation during Antarctic winter

Background: Persons with limited exposure to ultraviolet B light, including space travelers, may not receive enough vitamin D. Recent studies indicate that optimal serum 25-hydroxyvitamin D [25(OH)D] should be ≥80 nmol/L.

Objective: This study was designed to evaluate the effectiveness of 3 doses of vitamin D to raise and maintain 25(OH)D to a concentration >80 nmol/L in persons with limited ultraviolet B light exposure.

Design: This was a 5-mo, prospective, randomized, double-blind study of vitamin D supplementation. It was conducted during winter in Antarctica at the McMurdo Station, when ultraviolet B radiation levels are essentially zero. The 55 subjects were randomly divided into 3 groups for vitamin D supplementation: 2000 IU/d (n = 18), 1000 IU/d (n = 19), and 400 IU/d (n = 18). An additional 7 subjects did not take supplements or took supplements of their own choosing. Blood samples were collected about every 2 mo during the winter.

Results: About 5 mo after supplementation started, 25(OH)D increased to 71 ± 23 nmol/L in the 2000-IU/d group, 63 ± 25 nmol/L in the 1000-IU/d group, and 57 ± 15 nmol/L in the 400-IU/d group and decreased to 34 ± 12 nmol/L in the group not taking supplements.

Conclusions: These data will enable us to provide space crews with evidence-based recommendations for vitamin D supplementation. The findings also have implications for other persons with limited ultraviolet light exposure, including polar workers and the elderly.

L-Arginine supplementation improves exercise capacity after a heart transplant [Nutritional support]

Background: Endothelial dysfunction is associated with the decreased exercise capacity observed in heart-transplant (HTx) recipients. l-Arginine supplementation (LAS) stimulates the nitric oxide (NO) pathway and restores endothelial function.

Objective: We compared exercise capacity in healthy subjects and HTx patients and investigated whether chronic LAS might improve exercise capacity and NO/endothelin balance after an HTx.

Design: Clinical, echocardiographic, and exercise characteristics were measured in 11 control subjects and 22 HTx recipients. In a prospective, double-blind study, the 22 HTx recipients performed a 6-min exercise [6-min-walk test (6MWT)] and a maximal bicycle exercise test before and after a 6-wk period of placebo intake or LAS. Endothelial function was measured by analyzing blood NO metabolites, endothelin, and the resulting NO/endothelin balance.

Results: Exercise capacity decreased after transplantation. Unlike with the placebo intake, 6 wk of LAS improved quality of life in HTx recipients (mean ± SEM Minnesota Score: from 15.3 ± 1.3 to 10.6 ± 1.1; P < 0.001) and their submaximal exercise capacity. The distance walked during the 6MWT increased (from 525 ± 20 to 580 ± 20 m; P = 0.002), and the ventilatory threshold during the incremental test was delayed by 1.2 min (P = 0.01). Central factors such as resting stroke volume, systolic pulmonary arterial pressure, cardiac systolodiastolic functions, and heart-rate reserve were not modified, but LAS significantly increased the NO:endothelin ratio (from 2.49 ± 0.38 to 3.31 ± 0.39; P = 0.03).

Conclusion: Oral LAS may be a useful adjuvant therapeutic to improve quality of life and exercise tolerance in HTx recipients.

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