I know the question about Vit D supplements might have come up again and again. I myself have read and listened to your podcast about that, too. However, in the UK where I’m based, the NHS (National Health Service) still recommend us to take Vit D supplement for the winter time, would it be a solid advice from them?
Also, I’ve listen to podcast of some science-based fitness/influencer on the other day (He’s pretty solid but I don’t want to mention his name here). His advice is to take bloodtest regularly to see what supplements one should take, it seems to be against what BB Medicine advised that if we don’t have any symptom we shouldn’t take any random or regular bloodwork as it would do more harm than good? Do I understand it correctly or may I have missed any nuance?
I cannot give you personal medical advice regarding vitamin D, however I think it would be difficult to support a public health initiative of vitamin D supplementation with evidence. I do not think this is solid advice, though I can appreciate the complexity and difficulty that comes with making a public health recommendation. I think routine vitamin D testing and supplementation is likely not to be beneficial for most, though fortification of foods with vitamin D is likely beneficial for vulnerable individuals. People who are able to buy and take vitamin D supplements also tend to have better health trajectories for a myriad of reasons seemingly unrelated to vitamin D supplementation and/or its effects on vitamin D levels. Nevertheless, the supplement is relatively low risk at 400iu/day as the NHS recommends, provided the supplement comes from a company that tests its products through a third party.
A “blood test” can not tell an individual what supplements they would benefit from and is generally bad advice. It’s not possible for me to weigh-in on the totality of someone’s work, but that is not based in science at all and is very suspect.