Vitamin D supplementation can reduce risk of getting diabetes 2
Good news for those taking vitamin D for protection against COVID
Daily higher-dose vitamin D supplementation may help stave off diabetes in an at-risk population, researchers reported in a new article.
In a meta-analysis of three randomized clinical trials, vitamin D reduced the risk for type 2 diabetes by 15% in people with prediabetes according to Anastassios Pittas, MD, MS, of Tufts Medical Center in Boston, and colleagues.
This translated to a 3.3% (95% CI 0.6-6.0%) absolute risk reduction over the course of 3 years, the researchers wrote in Annals of Internal Medicine. Pittas' group also found that those who took vitamin D supplementation had a 30% increased likelihood of returning to normal glucose levels.
"Although the degree of relative reduction in risk for diabetes with vitamin D is small (15%) compared with other diabetes prevention strategies ... the 3-year absolute risk reduction was 3.3%, translating to a number of persons with prediabetes needed to treat of 30 (compared with 7 with intensive lifestyle modification and 14 with metformin in the Diabetes Prevention Program study)," the group said.
"Extrapolating to the more than 374 million adults worldwide who have prediabetes suggests that inexpensive vitamin D supplementation could delay the development of diabetes in more than 10 million people," they estimated.
When the three trials were combined, there was a total of 4,190 individuals: 2,097 who received vitamin D and 2,093 who received placebo. The average age was 61 years and 44% were women. About half were white, 15% Black, and 33% Asian. The average BMI was 29.5 and HbA1c was 5.9 at baseline.
Over the median 3-year follow-up, there were 475 new diabetes cases diagnosed among those taking vitamin D versus 524 across the placebo groups.
Those who maintained levels of at least ≥50 ng/mL) had a 76% reduced risk for progression to diabetes. This translated to a 3-year absolute risk reduction of 18.1%.
Reviewers noted that this "optimal effect" for vitamin D supplementation was seen above 4,000 IU daily.
Recommending a fixed quantity of vitamin D per day, such as 0.1 mg 4000 IU, makes no sense, even for a subset of the population identified as adults. Firstly there are a great range of bodyweights. Secondly, those suffering from obesity need to supplement vitamin D3 as a higher ratio of bodyweight than those who are not suffering from this partly inflammatory disorder, since their livers hydroxylate less of the vitamin D3 cholecalciferol to the circulating 25-hydroxyvitamin D the kidneys, immune system and other types of cell need - and their excess adipose tissue absorbs some of the vitamin D3 and 25-hydroxyvitamin D: https://vitamindstopscovid.info/00-evi/#obesity-deficit . This page cites and discusses the most pertinent research on vitamin D and the immune system.
Furthermore, the standard practice of recommending fixed quantities of vitamin D3 per day for children, based on their age, makes no sense - again due to the wide ranges of bodyweights and the potential for obesity.
Most official recommendations, such as the 2006 Australian ones: //www.eatforhealth.gov.au/nutrient-reference-values/nutrients/vitamin-d aim for a much lower circulating 25-hydroxyvitamin D level than 50 ng/mL 125 nmol/L, which is what the immune system needs to function properly.
There is only one set of vitamin D3 supplemental quantity recommendations in the peer-reviewed literature which firstly will get most people's circulating 25-hydroxyvitamin D levels safely over 50 ng/mL (after several months), secondly specifies the quantities as ratios of body weight and thirdly has a higher set of ratios for those suffering from obesity: "Rapidly Increasing Serum 25(OH)D Boosts the Immune System, against Infections - Sepsis and COVID-19", Sunil J. Wimalawansa, Nutrients 2022-07-21. https://www.mdpi.com/2072-6643/14/14/2997.
A table summarising the ratios is at: https://vitamindstopscovid.info/00-evi/#sjw-updated-ratios . See the https://vitamindstopscovid.info/00-evi/#obesity-deficit section for why I believe that underweight people should use the same range of ratios as those who have normal and overweight body types.
For emergency repletion of 25-hydroxyvitamin D levels in clinical emergencies, the best approach is a single oral dose of 0.014 mg calcifediol per kg bodyweight. Calcifediol _is_ 25-hydroxyvitamin D. This goes straight into circulation and attains at least 50 ng/mL 25-hydroxyvtimamin D in 4 hours. Prof. Wimalawansa's article recommends this. See also: https://nutritionmatters.substack.com/p/calcifediol-to-boost-25-hydroxyvitamin .