Vitamin D thread -Please use this for your Vit D info.

[sdstarfish]

Roz, my doctor has me on 5,000 iu daily.

[R.B.]

If anybody is in the UK and interested I am speaking at a Royal Society of Medicine food section conference on hidden nutritional deficiencies in my new role as recently appointed Chair of the McCarrison Society, which is a venerable society with its own widely recognized Journal 'Nutrition and Health'.

The Society has a long illustrious history, but is in need of a bit of revamping including a new web site.

I will be looking in whistle-stop fashion at deficiencies in nutrients particularly Iodine, Vitamin D, minerals, and imbalances in Omega 3 and 6 set within the context of the shoreline diet which arguably provided the conditions for out existence.

I am hoping to make the McCarrison Society a forum to bring together the Food Agricultural and Health sectors to the same table, which they never are, to try and bring focus on deficiencies such as Vitamin D, Iodine and secure the implementation of strategies to address them.



This is the link to the conference.

http://www.rsm.ac.uk/events/fhf01

[R.B.]

^ Very many thanks to anybody who attended. I understand the RSM copies of presentations to attendees, and I have given them permission to give out my slides. I hope at some point to do a longer presentation with a couple of additional slides that I hope to get put up on the web.


Why researchers keep using small amounts of vitamin D viz 400iu in expensive trials with the expectation of a significant change in outcome (except in groups that are seriously deficient) is somewhat of a puzzle to me.

What I then find most sad is a doctor saying to me (which happened yesterday) for example that they had seen a paper that looked at vitamin d in pregnancy and no effect was seen; I understand the amount trialled was 400iu,which is not in the scale of things going to produce a very significant change in vitamin D levels.

The conversation was fortuitous in so far as it fired me up and I found the papers below which contain very useful data which should be more widely available

[R.B.]

This may be of interest to those thinking about supplementing with Vitamin D and wanting information to share with their doctors. Breast cancer is specifically referred to in the discussion part of which I copy below. I also copy some data in healthy populations as to intake and outcome.

The paper is free and in full at the link below:



http://www.nutritionj.com/content/9/1/60

Impact of oral vitamin D supplementation on serum 25-hydroxyvitamin D levels in oncology

Pankaj G Vashi, Kristen Trukova, Carolyn A Lammersfeld, Donald P Braun and Digant Gupta*

"Background

Serum 25-hydroxyvitamin D [25(OH)D] is the major circulating form of vitamin D and a standard indicator of vitamin D status. Emerging evidence in the literature suggests a high prevalence of suboptimal vitamin D (as defined by serum 25(OH)D levels of <32 ng/ml) as well as an association between lower serum levels and higher mortality in cancer. We investigated the effect of oral vitamin D supplementation as a means for restoring suboptimal levels to optimal levels in cancer. "

"In order to put our study in context, we review here 3 studies in breast cancer that have evaluated the impact of vitamin D supplementation on serum 25(OH)D levels. Crew et al. examined the effects of standard-dose vitamin D supplementation on serum 25(OH)D levels in breast cancer patients. They observed that cholecalciferol 400 IU daily for 1 year raised serum 25(OH)D levels only modestly, by less than 3 ng/mL in only a small percentage of premenopausal women (< 15%). Although the RDA of vitamin D in premenopausal women is only 200 IU daily, their study suggested that a dose of 400 IU daily was inadequate in breast cancer patients, even to maintain skeletal health, and was probably too low for meaningful anticancer effects [28]. "


"When comparing it with the vitamin D dose response in healthy individuals, the literature yielded the following results. Talwar et al. showed that supplementation with 800 IU/d vitamin D3 in postmenopausal African American women raised the mean serum 25(OH)D concentration from a baseline of 18.7+/-8.2 ng/mL to 28.5+/-8.6 ng/mL at a 3 month interval [46]. In another study, Barger-Lux et al. showed that in a relatively replete group of white subjects, 1000 IU vitamin D3/d resulted in an increase of 5.2 ng/mL from a mean of 26.8 to 32 ng/mL [45]. Likewise Heaney et al reported a dose response of 0.28 ng/mL per 1 μg/40IU oral vitamin D3 supplemented [47]. Furthermore, Aloia et al. undertook a dose-finding study in African American and white men and women with the objective of investigating an algorithm for raising 25(OH)D concentrations to between 32 and 56 ng/mL. They suggested a dose of 3800 IU for those above a 25(OH)D threshold of 22 ng/mL and a dose of 5000 IU for those below that threshold [16]. "

[R.B.]

To convert nmol/l to ng/ml - divide by 2.5 (approx)

or 2.5nmol/l = 1ng/ml

Here is a link where they do it for you.

http://www.endmemo.com/medical/unitc...Vitamin__D.php

[R.B.]

This is a highly thought provoking and unusually data rich and so exceptional paper looking at the issue of vitamin D.

The second link; a table looking at vitamin D falls in submariners is highly thought provoking, as are all of the tables.

A definite recommend for a quick scan or more if you have the time for the data it presents.




http://ajcn.nutrition.org/content/69/5/842.full

Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and safety1,2

Reinhold Vieth

Many arguments favoring higher intakes of calcium and other nutrients have been based on evidence about the diets of prehistoric humans (1). Likewise, the circulating 25-hydroxyvitamin D [25(OH)D; calcidiol] concentrations of early humans were surely far higher than what is now regarded as normal. Humans evolved as naked apes in tropical Africa. The full body surface of our ancestors was exposed to the sun almost daily. In contrast, we modern humans usually cover all except about 5% of our skin surface and it is rare for us to spend time in unshielded sunlight. Our evolution has effectively designed us to live in the presence of far more vitamin D (calciferol) than what most of us get now, yet there is no consensus about what vitamin D intakes are optimal or safe.

See corresponding editorial on page 825.

Unlike anything else used in the fortification of foods, the purpose of vitamin D is to correct for what is an environmental deficit (less ultraviolet exposure) and not to correct for lack due to classical nutritional reasons. With a few exceptions reviewed by Takeuchi et al (2), there is little or no vitamin D in the kind of foods that humans normally eat. Therefore, conclusions about the efficacy and safety of vitamin D must be in the context of the role of environmental factors.

Before 1997, the recommended dietary allowance of vitamin D (RDA; 3) for infants and children was 10 μg (400 IU). In essence, the scientific basis for this dose was that it approximated what was in a teaspoon (5 mL) of cod-liver oil and had long been considered safe and effective in preventing rickets (4). The basis for adult vitamin D recommendations has been even more arbitrary. Thirty-six years ago, an expert committee on vitamin D could provide only anecdotal support for what it referred to as “the hypothesis of a small requirement” for vitamin D in adults and it recommended one-half the infant dose, just to ensure that adults obtain some from the diet (5). In England, an adult requirement of only 2.5 μg (100 IU)/d was substantiated on the basis of 7 adult women with severe nutritional osteomalacia whose bones showed a response when given this amount (6). The adult RDA of 5 μg (200 IU)/d was described as a “generous allowance” in the 1989 version of American recommended intakes (3)—but why was this “generous” and in relation to what? It is remarkable that despite the widespread intake of 5 μg (200 IU) vitamin D/d, there is still no published data showing that this dose has any effect on the serum 25(OH)D concentration in adults.



http://ajcn.nutrition.org/content/69...expansion.html

Decline in 25-hydroxyvitamin D [25(OH)D] concentrations under acutely sun-deprived living conditions

[R.B.]

https://www.youtube.com/watch?v=hiGBVDcbFVk

Another great lecture from Michael Holick