Discussion Board

Abstract

Effect of B-Vitamin Therapy on Progression of Diabetic Nephropathy
A Randomized Controlled Trial
Andrew A. House; Misha Eliasziw; Daniel C. Cattran; David N. Churchill; Matthew J. Oliver; Adrian Fine; George K. Dresser; J. David Spence
JAMA. 2010;303(16):1603-1609.

ABSTRACT

Context

Hyperhomocysteinemia is frequently observed in patients with diabetic nephropathy. B-vitamin therapy (folic acid, vitamin B6, and vitamin B12) has been shown to lower the plasma concentration of homocysteine.

Objective

To determine whether B-vitamin therapy can slow progression of diabetic nephropathy and prevent vascular complications.

Design,

Setting, and Participants A multicenter, randomized, double-blind, placebo-controlled trial (Diabetic Intervention with Vitamins to Improve Nephropathy [DIVINe]) at 5 university medical centers in Canada conducted between May 2001 and July 2007 of 238 participants who had type 1 or 2 diabetes and a clinical diagnosis of diabetic nephropathy.

Intervention

Single tablet of B vitamins containing folic acid (2.5 mg/d), vitamin B6 (25 mg/d), and vitamin B12 (1 mg/d), or matching placebo.

Main Outcome Measures

Change in radionuclide glomerular filtration rate (GFR) between baseline and 36 months. Secondary outcomes were dialysis and a composite of myocardial infarction, stroke, revascularization, and all-cause mortality. Plasma total homocysteine was also measured.

Results

The mean (SD) follow-up during the trial was 31.9 (14.4) months. At 36 months, radionuclide GFR decreased by a mean (SE) of 16.5 (1.7) mL/min/1.73 m2 in the B-vitamin group compared with 10.7 (1.7) mL/min/1.73 m2 in the placebo group (mean difference, -5.8; 95% confidence interval [CI], -10.6 to -1.1; P = .02). There was no difference in requirement of dialysis (hazard ratio [HR], 1.1; 95% CI, 0.4-2.6; P = .88). The composite outcome occurred more often in the B-vitamin group (HR, 2.0; 95% CI, 1.0-4.0; P = .04). Plasma total homocysteine decreased by a mean (SE) of 2.2 (0.4) µmol/L at 36 months in the B-vitamin group compared with a mean (SE) increase of 2.6 (0.4) µmol/L in the placebo group (mean difference, -4.8; 95% CI, -6.1 to -3.7; P < .001, in favor of B vitamins).

Conclusion

Among patients with diabetic nephropathy, high doses of B vitamins compared with placebo resulted in a greater decrease in GFR and an increase in vascular events.

Mass Media Article

B vitamin therapy leads to kidney function decline in kidney disease patients
Wednesday, April 28, 2010, 9:21

http://news.oneindia.in/2010/04/28/bvit ... -inki.html

Most of us do have take B12 as recommended by Dr M. So is that a problem?

This is covered in the beginning of the thread in my first few posts.

In Health
Jeff

I *HEART* this website! I especially enjoy the dry humor that is sometimes in the newsletters (and Jeff's posts). Thank you Dr. McD and Jeff!

High Doses of Antioxidant Supplements Induce Stem Cell Genetic Abnormalities, Study Finds

http://www.sciencedaily.com/releases/20 ... 173821.htm

ScienceDaily (May 4, 2010) — High doses of antioxidant nutritional supplements, such as vitamins C and E, can increase genetic abnormalities in cells, which may predispose supplement-takers to developing cancer, according to a new study from the Cedars-Sinai Heart Institute.

The study, led by Eduardo Marbán, M.D., Ph.D., director of the Cedars-Sinai Heart Institute, was published online in the medical journal Stem Cells. The study also will appear in the journal's July printed edition.

Marbán and his team accidentally discovered the danger of excessive antioxidant doses while seeking a way to reduce the genetic abnormalities that occurred naturally when the scientists sought to multiply human cardiac stem cells.

Marbán stressed that the study's finding applies only to excessive nutritional supplements and not to foods that are rich in antioxidants, such as milk, oranges, blueberries and peanuts. In recent years, multiple studies have touted the benefits of foods rich in antioxidants.

"Taking one multivitamin daily is fine, but a lot of people take way too much because they think if a little is good, a lot must be better," said Marbán, who is also the Mark Siegel Family Professor at Cedars-Sinai. "That is just not the case. If you are taking 10 or 100 times the amount in a daily multivitamin, you may be predisposing your cells to developing cancer, therefore doing yourself more harm than good."

In laboratories, stem cells are often grown in a Petri dish culture than is composed of 20 percent oxygen, whereas cells growing inside human tissue are exposed to just 3 to 5 percent oxygen. But Marbán's team of researchers became frustrated because the higher concentration of oxygen in lab-grown stem cells resulted in 9 percent of the cells being rejected because of genetic abnormalities.

"We sought to counter that oxidation problem by adding high doses of antioxidants directly to the cells," Marbán said. "That's when we made the serendipitous discovery that there is a danger zone for the cells exposed to antioxidants to develop genetic abnormalities that predispose to cancer."

Marbán is leading an ongoing, groundbreaking clinical trial in which heart attack patients undergo two minimally-invasive procedures in an effort to repair and re-grow healthy muscle in a heart injured by a heart attack. First, a biopsy of each patient's own heart tissue is used to grow specialized heart stem cells. About a month later, the multiplied stem cells are then injected back into the patient's heart via a coronary artery.

The two-step procedure was completed on the first patient in June 2009. The results of the trial are expected in early 2011.

Recently, Marbán received a $5.5 million grant from the California Institute for Regenerative Medicine to continue developing cardiac stem cell therapies.

Annual High-Dose Oral Vitamin D and Falls and Fractures in Older Women

A Randomized Controlled Trial

Kerrie M. Sanders, PhD; Amanda L. Stuart, BappSc; Elizabeth J. Williamson, MA, PhD; Julie A. Simpson, PhD; Mark A. Kotowicz, MBBS, FRACP; Doris Young, MD, MBBS, FRACGP; Geoffrey C. Nicholson, PhD, FRACP

JAMA. 2010;303(18):1815-1822.

ABSTRACT


Context Improving vitamin D status may be an important modifiable risk factor to reduce falls and fractures; however, adherence to daily supplementation is typically poor.

Objective To determine whether a single annual dose of 500 000 IU of cholecalciferol administered orally to older women in autumn or winter would improve adherence and reduce the risk of falls and fracture.

Design, Setting, and Participants A double-blind, placebo-controlled trial of 2256 community-dwelling women, aged 70 years or older, considered to be at high risk of fracture were recruited from June 2003 to June 2005 and were randomly assigned to receive cholecalciferol or placebo each autumn to winter for 3 to 5 years. The study concluded in 2008.

Intervention 500 000 IU of cholecalciferol or placebo.

Main Outcome Measures Falls and fractures were ascertained using monthly calendars; details were confirmed by telephone interview. Fractures were radiologically confirmed. In a substudy, 137 randomly selected participants underwent serial blood sampling for 25-hydroxycholecalciferol and parathyroid hormone levels.

Results Women in the cholecalciferol (vitamin D) group had 171 fractures vs 135 in the placebo group; 837 women in the vitamin D group fell 2892 times (rate, 83.4 per 100 person-years) while 769 women in the placebo group fell 2512 times (rate, 72.7 per 100 person-years; incidence rate ratio [RR], 1.15; 95% confidence interval [CI], 1.02-1.30; P = .03). The incidence RR for fracture in the vitamin D group was 1.26 (95% CI, 1.00-1.59; P = .047) vs the placebo group (rates per 100 person-years, 4.9 vitamin D vs 3.9 placebo). A temporal pattern was observed in a post hoc analysis of falls. The incidence RR of falling in the vitamin D group vs the placebo group was 1.31 in the first 3 months after dosing and 1.13 during the following 9 months (test for homogeneity; P = .02). In the substudy, the median baseline serum 25-hydroxycholecalciferol was 49 nmol/L. Less than 3% of the substudy participants had 25-hydroxycholecalciferol levels lower than 25 nmol/L. In the vitamin D group, 25-hydroxycholecalciferol levels increased at 1 month after dosing to approximately 120 nmol/L, were approximately 90 nmol/L at 3 months, and remained higher than the placebo group 12 months after dosing.

Conclusion Among older community-dwelling women, annual oral administration of high-dose cholecalciferol resulted in an increased risk of falls and fractures.

(NOTE: 500,000 IU is the equivalent of about 1350 IU/Day)