Two articles on PainSci cite Heaney 2008: (1) The Complete Guide to Trigger Points & Myofascial Pain (2) Vitamin D for Pain
PainSci notes on Heaney 2008:
How much Vitamin D supplementation is enough? How much is too much? “The input needed for efficacy, in addition to typical food and cutaneous inputs, will usually be 1000-2000 IU/day” and “toxicity is associated only with excessive supplemental intake (usually well above 20,000 IU/day).” This paragraph from the article on toxicity and safety is particularly relevant:
Both the intoxication literature and the recent controlled dosing studies have been reanalyzed by Hathcock et al. These authors show that essentially no cases of confirmed intoxication have been reported at serum 25(OH)D levels below 500 nmol/L. Correspondingly, the oral intakes needed to produce such levels are in excess of 20,000 IU/day in otherwise healthy adults and, more usually, above 50,000 IU/day. These findings led Hathcock et al to select 10,000 IU/day as the tolerable upper intake level (TUIL, or UL), with considerable confidence. It is likely that a higher intake could be defended, but little good would be served by doing so, as 10,000 IU/day is substantially more than is apparently needed for any recognized efficacy endpoint.
original abstract †Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.
The functional status indicator for vitamin D, for both safety and efficacy, is serum 25-hydroxyvitamin D concentration. Efficacy for several health endpoints requires levels of 80 nmol/L or higher. Toxicity occurs at levels of 500 nmol/L or higher. The input needed for efficacy, in addition to typical food and cutaneous inputs, will usually be 1000-2000 IU/day of supplemental cholecalciferol. Toxicity is associated only with excessive supplemental intake (usually well above 20,000 IU/day).
This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights:
- Modulation in the elastic properties of gastrocnemius muscle heads in individuals with plantar fasciitis and its relationship with pain. Zhou 2020 Sci Rep.
- Association Between Plantar Fasciitis and Isolated Gastrocnemius Tightness. Nakale 2018 Foot Ankle Int.
- Effectiveness of customised foot orthoses for Achilles tendinopathy: a randomised controlled trial. Munteanu 2015 Br J Sports Med.
- A Bayesian model-averaged meta-analysis of the power pose effect with informed and default priors: the case of felt power. Gronau 2017 Comprehensive Results in Social Psychology.
- The neck and headaches. Bogduk 2014 Neurol Clin.