Oral intake of vitamin B3 could potentially help prevent acute kidney injury that affects 30-40 per cent of all hospitalised adults in the low-income countries, suggests a study, led by a researcher of Indian-origin. Acute kidney injury, an often fatal condition without a specific treatment, causes a build-up of waste products in the blood and an imbalance of fluids throughout the body. The findings showed that levels of nicotinamide adenine dinucleotide (NAD+) - the end result of vitamin B3 after it is ingested - declines in cases of acute kidney injury. "We were able to detect a drop in NAD+ in the urine of high-risk patients who were either in an intensive care unit or undergoing a major surgery and found that oral vitamin B3 could safely elevate NAD+ in high-risk patients," said principal investigator Samir M. Parikh, nephrologist and associate professor at Harvard University. "These findings are very early, but the results suggest that we could one day have a non-invasive test for NAD+ status and perhaps even treat acute kidney injury by boosting NAD+ levels," he added. In the study, published in the journal Nature Medicine, the team examined the metabolic changes associated with acute kidney injury in a mouse model. A urine screen revealed high levels of quinolinate. They then created a mouse model with reduced QRPT - an enzyme responsible for converting quinolinate to NAD+ - but no kidney injury. The genetically altered rodents mimicked the pattern of acute kidney injury; decreased NAD+, increased urinary quinolinate and increased susceptibility to kidney injury. The experiments were the first to establish QRPT as a mediator of renal stress resistance. In subsequent human studies, the team found high urinary quinolinate in patients undergoing major surgery at risk for acute kidney injury and confirmed this metabolite pattern in a separate study of 329 intensive care unit patients also at risk for acute kidney injury. The team then gave large doses of oral vitamin B3 to 41 cardiac surgery patients enrolled in a Phase 1 pilot study and found that augmenting vitamin B3 levels may be safe and potentially beneficial to patients.