Occasionally I read stuff that makes me angry. Really angry. Moronic popular media pseudoscientific articles “debunking”, “educating” and “linking nutrient x with disease z” normally fall into this category. The award for the popular media article with the dumbest headline and the most questionable content of the month goes to NZ Herald article “Researchers write off benefits of vitamin D“.
Researchers who have debunked one of the claimed benefits of vitamin D capsules are sceptical of the links that have been made to a much wider range of medical conditions.
Auckland University physician Professor Ian Reid and colleagues concluded after studying 23 trials that most healthy adults need not take vitamin D supplements for the prevention of the bone-weakening condition osteoporosis.
Let’s start with the headline. The researchers DID NOT “write off the benefits of vitamin D”! The article relates to vitamin D SUPPLEMENTATION. Unfortunately we use the term “vitamin D” interchangeably with the pro-hormone 25(OH)D that we synthesise in our own bodies and with the white pill that you can take orally to supplement your serum levels of this. Still, shouting out “there are no benefits to vitamin D” is extremely stupid and deceptive. All vertebrates have to synthesise vitamin D to survive, and have been doing so for over 350 million years.
I have not got access to the actual study (only the abstract) so I will reserve the judgement on the paper. Let’s have a deeper look into this NZ article instead (it may very well be that it doesn’t fully reflect the authors’ conclusions).
Love this sentence:
Use is said to be very high among patients of GPs in wealthier areas.
That, I assume, either implies that GP are trying to scam their more affluent patients into buying a totally unnecessary supplement, or that health-conscious and gullible wealthy worried-well are using vitamin D in addition to their chiropractic appointments, yoga retreats, and other voodoo. Both are pretty insulting implications.
They have become something of a cure-all – or prevent-all – with low blood levels having been linked to multiple sclerosis, winter colds, heart disease, cancer, mental illness and numerous other medical conditions. Professor Reid has found reports of links to 53 conditions.
‘When you get 53 different diseases associated with low vitamin D levels and when those diseases are incredibly disparate … it’s pretty hard to see a common biological explanation for those associations except the fact that people don’t go outside and lie around in the sun [when they are sick].’
Hmmm. 53 “incredibly disparate” conditions linked to low vitamin D levels. That does sound rather suss. That’s, like, this is miracle vitamin, or something. What could possibly all these conditions have in common???
Erm. I assume Professor Reid has heard of inflammation. And I hope that Professor Reid is familiar with the extensive body of research looking at vitamin D as much more than just a “bone-building vitamin” but a powerful immunomodulator. Its method of action is so broad that vitamin D receptor (VDR) is expressed by the cells in most organs of the body: intestines, bone, kidney, skin, brain, heart, breast, parathyroid glands and gonads.
This from the Scandinavian Journal of Clinical and Laboratory Investigation (Reichrath et al, Hope and challenge: The importance of ultraviolet (UV) radiation for cutaneous Vitamin D synthesis and skin cancer, 2012)
Of high importance was the discovery that in contrast to earlier assumptions, skin, prostate, colon, breast, and many other human tissues not only express the vitamin D receptor (VDR) but also express the key enzyme (vitamin D-1 α OHase, CYP27B1) to convert 25(OH)D to its biologically active form, 1,25(OH) 2 D [1,2,6]. This active vitamin D metabolite is considered as an not exclusively calciotropic hormone, but additionally as a locally produced potent secosteroid hormone regulating various cellular functions including cell growth and differentiation.
Cell growth and differentiation: that may have something to do with all those cancers, huh?
No, there is no plausible biological explanation at all.
Not sure why Professor Reid mentions any of these conditions at all since his paper actually only looked at the effect of vitamin D supplementation and the risk of osteoporosis. I am going to take a stab in the dark and say that osteoporosis is a multifactorial disease. From the abstract it transpires that 10 of the studies analysed use such piddly doses of vitamin D as 800IU. I wonder why they even bothered. For the populations in question the typical doses of 600IU to 1000IU of cholecalciferol barely going to maintain their levels, let alone increase them significantly. Compare this to 10,000IU your body can potentially synthesise from 30 minutes of direct sunlight.
Most healthy adults in New Zealand got enough vitamin D from the sun, said Professor Reid.
Riiiight. This may indeed be the case in sunny tropical New Zealand but here in Australia we have a few issues with vitamin D deficiency.
Research by Deakin University found that one third of Australians is now vitamin D deficient. The authors of this 2009 paper were quite alarmed by this fact, seeing it as a “major health problem worldwide”:
Low levels of vitamin D can contribute to a number of serious, potentially life-threatening, conditions such as softened bones; diseases that cause progressive muscle weakness leading to an increased risk of falls, osteoporosis, cardiovascular disease, certain types of cancer and type 2 diabetes.
One thing on which I will agree with Professor Reid. Popping vitamin D pills is not the answer. Some the links between vitamin D deficiency and various conditions are undoubtedly related to changes in our lifestyle. Going out for a walk in nature will not only top up your vitamin D levels but will boost your cardiovascular fitness, strength, circulation, and promote overall mental health and wellbeing. The whole is always more the sum of its parts. And this is supported in the literature. This systematic review, for example, concludes that cancer prevention related to sunlight, cannot be fully explained by the vitamin D effects alone. Just like with our diet, we should aim to receive all the necessary nutrients naturally. Ideally we will get most of our vitamin D through sunlight exposure and, to a much smaller extent, diet. However many of us work indoors from 9am to 5pm without ever seeing sunlight. Supplementation is sometimes necessary.
Irresponsible reporting such as this can cost somebody their health.