www.vitadigest.com Live Stats: 67,168 Quality Products by 1,866 Premier Brands
View All Return to Page View Grid View Grid View List View List View
Grid View Grid View List View List View
D-Ribose is a naturally occurring five-carbon sugar found in all living cells, as well as in RNA-containing viruses. It is not an essential nutrient, since it can be made in the body from other substances, such as glucose. D-ribose, however, is very essential for life. Some of the most important biological molecules contain D-ribose, including ATP (adenosine triphosphate), all the nucleotides and nucleotide coenzymes and all forms of RNA (ribonucleic acid). D-ribose, in the form of ribonucleoside diphosphates, is converted to deoxyribonucleoside diphosphates, precursor molecules for DNA. D-ribose in RNA and D-deoxyribose in DNA may be considered genetic sugars.
Since D-Ribose is ubiquitous in living matter, it is ingested in our diets. Such nutritional substances as brewers yeast are rich in RNA and are thus rich sources of D-ribose. Some recent research suggests that supraphysiological amounts of this sugar may have cardioprotective effects, particularly for the ischemic heart.
D-Ribose is a sweet, solid, water-soluble substance that is also known as alpha-D-ribofuranoside. L-ribose does not have biological activity. D-ribose is sometimes referred to as just ribose. Supplemental D-ribose is produced from the fermentation of corn syrup.
ACTIONS AND PHARMACOLOGY
Supplemental D-ribose may have metabolic cardioprotective activity. It may also enhance de novo purine biosynthesis.
MECHANISM OF ACTION
Following a cardiac ischemic event, ATP levels in the heart decline rapidly and are slow to rebound. 5-Phosphoribosyl 1-pyrophosphate (PRPP) is a key intermediate in the de novo and salvage pathways of purine nucleotide formation, as well as a key intermediate in synthesis of pyrimidine nucleotides. PRPP is the biochemically activated form of D-ribose and is synthesized from D-ribose-5-phosphate, which is produced in the oxidative pentose phosphate pathway (PPP). The limiting step in the PPP is the glucose-6-phosphate dehydrogenase (G-6-PD) reaction. The G-6-PD reaction can be bypassed with D-ribose. In supraphysiological amounts, D-ribose may serve as a precursor to PRPP, which then allows for de novo synthesis of purine nucleotides, including ATP. D-ribose infusion has been shown to significantly enhance the recovery of energy levels in the post-ischemic myocardium in animal models.
About 88% to 100% of an oral dose of D-ribose, up to 200 milligrams per kilogram per hour, is absorbed from the small intestine, from whence it is distributed to various tissues of the body, including cardiac muscle and skeletal muscle. Very little first-pass metabolism occurs in the liver. Following transport into cells, D-ribose is phosphorylated to D-ribose-5-phosphate. D-ribose-5-phosphate is metabolized via a number of pathways, including the pentose phosphate pathway and glycolytic pathway. Its metabolism is complex. It is also metabolized to PRPP, which is the precursor to purine nucleotides, as well as L-histidine and pyrimidine nucleotides. Those receiving very high doses of D-ribose excrete a small fraction of the administered dose unchanged in the urine.
INDICATIONS AND USAGE
D-ribose may have some protective effects in cardiac ischemia. Claims that it is an effective 'energizer' and exercise-performance enhancer are not substantiated by credible evidence. D-ribose may also be beneficial in some rare genetic diseases, such as adenylosuccinase deficiency and myoadenylade deaminase deficiency.
In a study of 20 men (aged 45 to 69 years) with documented severe coronary artery disease and a history of angina induced by normal daily activities, 60 grams of ribose (in four doses of 15 grams each) were tested against placebo. Treated subjects exhibited improvement as measured electrocardiographically, and time to onset of moderate angina (during exercise testing) increased significantly in those ribose-treated subjects. There was no significant electrocardiograph improvement in the placebo group, and there was no significant difference between the groups in time to onset of moderate angina. The authors concluded: 'In patients with CAD, administration of ribose by mouth for three days improved the heart's tolerance to ischemia. The presumed effects on cardiac energy metabolism offer new possibilities for adjunctive medical treatment of myocardial ischemia.'
Claims that supplemental ribose is an energy booster and exercise/athletic-performance enhancer are unfounded. Studies sometimes cited in support of these claims fall far short of being substantiating. It has been shown that administration of ribose in patients with myoadenylate deaminase deficiency disease can reduce cramping and stiffness caused by exercise. On the other hand, in a double-blind, placebo-controlled crossover trial of ribose in McArdle's disease, 60 grams of ribose daily for seven days failed to improve exercise tolerance in these subjects. Finally, there is one case report of a patient with adenylosuccinate deficiency whose neurological symptoms (behavior and seizure frequency) improved with supplemental D-ribose.
Pregnant women and nursing mothers should avoid supplemental D-ribose.
Supplemental D-ribose may cause hypoglycemia and elevation in uric acid levels. Those with gout should avoid supplemental D-ribose, and those with elevated uric acid levels and hypoglycemics should exercise extreme caution in its use. Those with diabetes should also exercise extreme caution in its use. And those diabetics who decide to try D-ribose must be under a physician's supervision and have their blood glucose levels closely monitored and their antidiabetic medications appropriately adjusted, if necessary.
Reported adverse reactions include hypoglycemia, hyperuricemia, hyperuricosuria, diarrhea, nausea and headache.
Antidiabetic drugs: D-ribose may cause hypoglycemia. Diabetics who use D-ribose must have their blood glucose levels closely monitored and their antidiabetic s appropriately adjusted, if necessary.
What Our Customer Say...
*Disclaimer: Statements made, or products sold through this website, have not been evaluated by the United States Food and Drug Administration. They are not intended to diagnose, treat, cure or prevent any disease. The information provided on this site is for informational purposes only and is not intended as a substitute for advice from your physician or other health care professional.*
Products image are NOT always exactly as shown on the photographs. We try to be as accurate as possible with photos. Please check the Title carefully before ordering.
All models are 18 yrs or older.
Copyright © 2008-2023 VitaDigest.com. All Rights Reserved.