Back in May, one of my blogs focused on some evidence which suggests that vitamin D has the capacity to improve a range of measures of physical function, including fitness, muscular strength, balance and reaction time. Strange though this may seem, there indeed appears to be evidence that simply sitting the sun may be all it takes to get fitter and healthier.
Of course, not everyone has the opportunity to sit out in the sun. Some parts of the World, particularly during colder seasons, don’t get that much sun. And even in places where the sun is shining, some individuals may be shielded from it through clothing or by the fact that they’re sitting inside. One subset of the population prone to problems here is the elderly. As people get older they can also get out less, perhaps at least partly because of increasing infirmity or disability. Some elderly individuals can end up a bit institutionalised, even in their own home.
This, in theory, may set up a bit of a vicious cycle. As people get increasingly infirm they are less likely to get out, and are more likely to become vitamin D deficient as a result. This, in its own way, may contribute to weakness and infirmity, which makes venturing out into the light even less likely. And so the cycle repeats.
I thought about this recently on reading about a study in which institutionalised Brazilian individuals aged 60 or more were treated with calcium, plus either vitamin D (D3) or placebo [1]. Vitamin D was given at a dose of 150,000 IU once a month for two months, followed by 90,000 IU once a month for a further four months. Two muscle tests were performed at the start and end of the study. One of these tested the muscles that flex the hip (the motion of lifting the knee in the standing position). The other tested the strength of the ‘knee extensors’ (straightening of the leg at the knee).
The calcium/placebo supplemented group did not see improvements in either of these two measurements. The group taking did:
Hip flexion strength increased by 16.4 per cent
Leg extension strength increased by 24.6 per cent
Both improvements were statistically significant.
The authors of the study conclude that The suggested cholecalciferol [D3] supplementation was safe and efficient in enhancing 25(OH)D [vitamin D] levels and lower limb muscle strength in the elderly, in the absence of any regular physical exercise practice.
Here again, it seems we have evidence that vitamin D has the capacity to improve muscle strength. This, I think, has important implications for those who could do with a bit more muscle strength such as many elderly individuals.
Remember, vitamin D has been linked with improved reaction time and balance too. Higher vitamin D levels may therefore help protect the elderly against falls ” something that could help to prevent injury, including broken bones, and even death.
References:
1. Moreira-Pfrimer LD, et al. Treatment of Vitamin D Deficiency Increases Lower Limb Muscle Strength in Institutionalized Older People Independently of Regular Physical Activity: A Randomized Double-Blind Controlled Trial Ann Nutr Metab 2009;54(4): 291-300
William Davis, MD says that vitamin D3 gelcaps work at improving blood levels of D but the tablets don’t work consistently. Seems like a very simple study would determine if that’s true or not. Lots of people take the tablets as they are cheaper.
John, I hadn’t been able, in the few minutes available before I shoot off to work, to locate visitor contribution that postulated a possible evolutionary basis and advantage for a degree of ‘seasonal metabolic dynamism’ as a physiological response to seasonal variation in dietary inputs and factors.
Some had interpreted my earlier contributions upon the role of Vitamin D as outright scepticism though really I was only being sceptical about such an overt relationship.
The artificial sweetener thread set me off thinking and I’m inclined to voice some under-explored and under-developed speculation.
As you know my interest is the exploration of human dietary pre-history and the belief that contrasts with the modern day could be illuminative.
One of my own investments is that past prominent dietary inputs supplied cabs and proteins (with the presence of much fibre) in a broad and intrinsic balance (foliar foods and nuts).
The sweetener thread has prompted the observation that there is cause to think the seasonal availability of the sweetest and most sugar rich foods (ripe fruits) would likely correlate to (perhaps following just a few weeks on from) the greatest seasonal ability to synthesise vitamin D.
This postulation would be a basis to add support to the role of vitamin D in the broader sense of matabolic regulation – but one relationship may add complication; that of the carb-cholesterol link, if any, and this on the basis of the involvement of cholesterol as a founding cursor in it D synthesis.
Puzzling… I’m hooked, and really appreciative of your efforts and blog.
read your blog eagerly….thank you….
i’m u k based, rural area….go to boots the chemist [ like many people ]….their vit d called strong is labled 12.5 [grams?]…..how do i work out the i.u.’s that you quote…. and is it the best vit d…..and are there any reasons not to self prescribe…..
agree withmazza, clarification needed as to what a daily dose would be. Find the various ugs/ius very confusing
Daily I take Solgar D3 (10ug) (400iu) which would appear to be but a blip in the ocean compared to the levels quoted – am I wasting my time.
Your guidance greatly appreciated
Thank you
Shelagh Brady
mazza
1 ug = 40 IU so 12.5 ug = 500 IU. can’t comment on the quality of Boots’ vitamin D (don’t know it) but I’ve read that oil-filled gelcaps are the best source (and these are what I take).
shelagh
whether or not you are wasting your time depends, to a degree, on whether the supplement you are using at your current dose is optimising your vitamin D levels, and the only way to tell that is to have appropriate testing. In all likelihood, though, the dose you are currently taking is likely to be leaving you with suboptimal levels of vitamin D.
“John, I hadn’t been able, in the few minutes available before I shoot off to work, to locate visitor contribution that postulated a possible evolutionary basis and advantage for a degree of ‘seasonal metabolic dynamism’ as a physiological response to seasonal variation in dietary inputs and factors.”
That might have been me, but AFAICR I was replying to someone else on the same subject.
I can’t find it now but I have a paper on Sedge Warblers which can double their body weight eating plum reed aphids (high carb insects full of plant sap) prior to migrating, and other insectivorous species may fill up on berries to gain fat as fuel for a trans-Saharan migration. This suggests some metabolic switch, maybe flipped by changing daylength. Probably hibernating animals do the same trick: turn on insulin resistance and gain fat rapidly, then turn it off, reduce metabolic rate, and live off the fat stores.
Ah, here is that earlier thread and comment on the seasonal. Pure speculation on my part, but with gratitude to TW for a natural perspective and submission that confers some agreement.
One would have an expectation of day length and vitamin D to have an involvement.
Seasonality and metabolic shift would not be so pertinent to us in the modern day save for as a talking point and the potential insight it may cast upon the nature 21st century weight gain. It does make nature fascinating. I’m starting an interest to late in life, I feel.
I decided to move up from a simple multi-vitamin and decided to go with the best on the market, which is the Dr Max Powers “Anabolic Stack”. The more I research, the more I realize it is a good idea to suppliment the diet with a good multi.
Since I am the gym and working out quite a bit, I could justify stepping up to the Dr Max Anabolic Stack. I have been taking them for almost 3 weeks and seem to have additional energy. I have had no side effects at all and have gotten used to taking all the pills in the morning.
I recommend this product for those that are active and want to ensure they are meeting all their vitamin and mineral needs. If this doesn’t cover it.. nothing will!