Vitamin D-heard this today anyone?

[2019pro]

speciality.medicaldialogues...

[HeronNS]

Interesting. I wonder if it's like any other micronutrient? It works synergistally with other nutrients and too much of one is counterproductive (eg we need to take in more magnesium with calcium supplements or we end up with a magnesium deficiency). Vitamin D isn't actually much use for bones unless we get adequate Vitamin K2 (and magnesium) as D does not send calcium to the bones. The other substances do that. So it would be interesting to know more about the actual context of the study.

[Met00]

I saw a link on a Facebook group today to the actual study: jamanetwork.com/journals/ja.... None of the participants had osteoporosis, the average blood level of Vit D before they started supplementing was very healthy (around 80nmol/litre = 32ng/ml, though range 30nmol/litre to 125nmol/litre), and there's no mention of taking co-factors such as Vit K which are essential to direct calcium (absorbed as a result of Vitamin D supplementation) to the bones. The study appears to show a drop in blood D level in the 10,000iu per day supplement group later in the study, but if you read further, it turns out that the manufacturer changed the supplement and the group were actually only receiving 2000 to 10000iu daily (average 6000). From the study: "participants with osteoporosis or with 25(OH)D levels of less than 30 nmol/L were excluded from this study. It is possible that participants with osteoporosis or low 25(OH)D levels would have responded differently to high-dose vitamin D supplementation, which would need to be explored following a different study design." In other words, we might as well ignore this!

[yogalibrarian in reply to Met00]

Good for you! It's really important to go back to the original research (or at least the original press release from the researchers) rather than relying on the story filtered by the media.

What struck me was the high doses of vitamin D -- much higher than the standard recommendations -- and that it excluded participants with osteoporosis.

I'd have to reread the research, but I don't think that particpants were vitamin D-deficient, based on blood tests.

[Mark_ABH]

We discussed this study with the experts on our Medical & Scientific Advisory Board. The bottom line is there are many good reasons to take vitamin D supplements -- but preventing fractures is not one of them.

One of them, an endocrinologist, said the study was silly because why would you take 10,000 IU/daily of Vitamin D to prevent fractures when there are perfectly good FDA-approved osteoporosis medications for this purpose?

This study is also in line with larger data trials that are already out there. Here's an article about the current U.S. guidelines, which do not recommend even 400 IU/daily of Vitamin D to prevent fractures. americanbonehealth.org/nutr...

[HeronNS in reply to Mark_ABH]

If Vitamin D actually worked to prevent fractures I'd certainly take it in preference to any osteoporosis drug.

[2019pro in reply to HeronNS]

I tend to agree with you on that....

[Met00 in reply to HeronNS]

Vitamin D plays an important role in absorbing calcium, so if Vitamin D is low, our bones are likely to lack calcium, ie develop osteoporosis. The question remains though as to how much Vitamin D is needed. The following chart suggests that a blood level of around 125nmol/litre (50ng/ml) is effective for reducing the incidence of many diseases, including a reduction in fracture rate grassrootshealth.net/docume...

[Jessie1234 in reply to Met00]

Thanks Met00 for the very useful information.