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.
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 .
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 .