DWQA Questions › Tag: U-shaped curve
Filter:AllOpenResolvedClosedUnanswered
A viewer asks: “Being aware of Creator’s previous answers on Vitamin D3 supplementation I was shocked to discover a paper from 2014 “A Statistical Error in the Estimation of the Recommended Dietary Allowance for Vitamin D”. The paper claims that the Recommended Daily Allowance advocated by the Institute of Medicine for Vitamin D was incorrectly calculated! In fact, analyzing the data correctly, nearly 9000 IUs per day are required to achieve target levels (600 IU per day is the USA recommended level). I was struck by how closely the 9000 IU figure matched Creator’s “daily doses of 5,000 to 10,000 IU vitamin D3 will rarely be harmful.” What is Creator’s perspective on this “miscalculation” coming to light?”
ClosedNicola asked 3 weeks ago • 
62 views0 answers0 votes
A British group reported recently that administration of vitamin D2, which is converted to vitamin D3 by the body, may be disadvantageous. A review of random controlled trials showed that taking vitamin D2 can lead to a decrease in vitamin D3 levels, the more active form generated by sunlight exposure. The research indicates that D2 supplementation may not only be less effective, but can also lead to lower concentrations of D3 in the circulation. [Emily I G Brown, et al. Effect of Vitamin D2 Supplementation on 25-Hydroxyvitamin D3 Status: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutr Rev, 2025 Sep 18:nuaf166.doi: 10.1093/nutrit/nuaf166]. Is this an accurate and meaningful assessment? What is most important for us to know?
ClosedNicola asked 3 weeks ago • 
62 views0 answers0 votes
Studies have shown that vitamin D levels have an inverted U-shaped curve, where low levels (<29.7 nmol/L) result in shortened telomeres on DNA, a sign of aging, but so do high levels of vitamin D (>95.9 nmol/L). Population-based studies and randomized clinical trials have shown a U- or J-shaped curve and suggested an increased risk of adverse outcomes in those with the highest serum Vitamin D levels, including falls, fractures, and frailty. Most studies have reported a higher risk in those participants with serum levels above 100 nmol/L. Are the deleterious effects noted in these studies caused by elevated vitamin D? If so, your support for taking 5,000 to 10,000 IU of vitamin D3 daily seems risky. What is most important for us to know?
ClosedNicola asked 2 months ago • 
60 views0 answers0 votes
Ask Question