Vitamin D overdoses

I got into a conversation with some people on Twitter over this past weekend, after commenting on an article about people overdosing on vitamin D.

The article talked about a man who overdosed on vitamin D on the advice of a nutritional therapist. Not a doctor!

According to the article:

This particular case concerns a middle-aged man who was referred to the hospital by his family doctor after complaining of recurrent vomiting, nausea, leg cramps, abdominal pain, increased thirst, dry mouth, tinnitus (ringing in the ear), diarrhoea, and weight loss (28 lbs or 12.7 kg).

And he'd been taking high doses of more than 20 supplements. Blood tests revealed his vitamin D levels being seven times higher than needed for sufficiency.

Back to Twitter, I made the point that people shouldn't take vitamins willy-nilly. That the end result is usually expensive urine, and that supplementation is usually useless unless your doctor has identified something you're actually lacking.

The vitamin D issue is quite serious. Many alternative practitioners have been recommending vitamin D supplementation as a way to ward off Covid-19. So likely there's a rise in its use for this reason.

My Twitter conversation then evolved into claims that “not all supplements” are lacking in evidence. They linked to a Hardy Nutritionals site (they're a multinational), for a product called Daily Essential Nutrients.

The recommended dose is 12 capsules a day. I found the product available on a NZ-based website for $198. That's a pretty expensive product, so I'd be wanting pretty good evidence of efficacy.

They claim to have studies that support their use in treatment for conditions such as ADHD, Autism Spectrum Disorders, OCD and anxiety disorders. Such studies, written in scientific language, are difficult for the layperson to interpret. (And, with a quick glance as the studies cites, many of them have small sample sizes, or concentrate on simply demonstrating safety of the product. Indeed one of the studies linked to showed a result of increased growth of kids with ADHD when on the product - a result that may be somewhat irrelevant to whether it helps treat symptoms!)

To me this presents a dilemma for skeptics. There are many topics we are certain about - such as psychics being wrong, or perpetual motion machines violating the laws of physics. But, for topics we're less “expert” on, such as the role of food in medicine and the use of supplements, we should be more cautious. It's very easy for those convinced of the efficacy of such products to find support from a scientist or a particular study. There are outlier scientists in every field. What matters is the consensus of expert scientific opinion. Yes, that single scientist could be the next Galileo, but the burden of proof is on them to first convince their own scientific community of the value of their research.

It appears to be very easy for commercial operations, such as nutritionals manufacturers to make the leap from some initial, tentative research into making products that satisfy the “worried well” people. People with money to throw at products that offer the potential to enhance wellbeing without having to conclusively demonstrate that.

Micronutrients are defined as the vitamins and minerals that the body needs in very small amounts. Being deficient in these can result in severe and even life-threatening conditions. That being said, it certainly doesn't follow that mega-dosing on these micronutrients will have any beneficial effect. And, as we've seen above, can have severe detrimental effects. As I said earlier, you need some sort of test from a qualified medical professional to identify deficiencies. Eating a reasonable quality diet is most likely to provide you with everything you need. There are, of course, specific types of diets where this might not be the case, but again, you're going to get much better advice from a qualified professional than a “nutritional therapist”.

My Twitter conversation threw up an interesting comment:

…Anyway my sister gives it to her very ADHD son and thinks it has made an improvement (he's also on proper medication).

Which makes me think that it would be difficult to tease apart the effect of the “proper” medication vs the supplement, especially with a sample size of one. It's akin to the cancer patient on chemo attributing their remission to prayers or the herbs they took at the same time!