Tuesday, May 26, 2009

Grassroots Health Vitamin D Study Seeks Participants

Before I get on with the other nine problems people have when implementing paleo diet, I wanted to pass along a link to the website of Grassroots Health, an organization that has organized an open study of vitamin D and health under the auspices of leading vitamin D scientists. From the site:

GrassrootsHealth has launched a worldwide public health campaign to solve the vitamin D deficiency epidemic in a year through a focus on testing and education with all individuals spreading the word.

Everyone is invited to join in this campaign! Join Daction and test two times per year during a 5 year program to demonstrate the public health impact of this nutrient.

$40 and a quick health survey allows everyone to

  • get a vitamin D blood spot test kit to be used at home (except in the state of New York)
  • have the results sent directly to them
  • take action to adjust their own levels to get to the desired ranges with whatever help is needed from their healthcare practitioners.

With only 100 people joining up today, and getting 2 friends to join in 2 weeks (and those 2 friends getting 2 more), by week 42, there could be 400,000,000 people who are vitamin D ‘replete’! (more than the United States population)

I signed up. As a participant, you pay $40 every 6 months to receive a vitamin D lab test delivered to your door, and you agree to fill in some surveys along the way, over a 5 year period. You can't beat the price for the vitamin D test, and your participation will contribute greatly to our understanding of the health protective effects of vitamin D.


Ken said...

"leading vitamin D scientists"

Some scientists were enthusiastic about antioxidants until they did trials, (some of which were stopped due to excess mortality).

If relatively high vitamin D levels are so very good for you - why would genes for the trait of high levels not have become virtually universal.

"adjust their own levels to get to the desired ranges"

Evolution by natural selection tends to take care of business. Mad dogs and ....

Take care it doesn't turn into a 'pushing up the' Grassroots study.

Don said...


I have to say I wasn't terribly impressed by Peter's post at Evo and Proud. It did have some interesting research (like finding increased mortality with levels over 50 ng/ml) so I can see some caution needed, and I will keep an active mind about this, but I saw a number of reasons to question his direction.

I don't find Binkley et al (quoted by Peter) that convincing. Near the end they state:

"Finally, this study was conducted following the Hawaiian equivalent of winter during which time there is reduced capability for cutaneous vitamin D production. "

They then go on to say that 60 ng/ml is the maximum safe upper limit based on their own data. But they need to take the same measurements at the end of Hawaiian summer before they conclude that 60 ng/ml is the maximum attained by sun exposure.

In the Nebraska study, You find the high levels at the end of the summer then it falls to low levels. It is natural for the levels to fall throughout the dark months as the body uses VT-D while not producing much if any.

In the India study, you have people living largely on grains, which induce vitamin D deficiencies and bone mineral abnormalities in a wide variety of animals
(1-3) including primates (4)."

It appears that cereal grains have an ability to interfere with the entero-hepatic circulation of vitamin D or its metabolites (4,5), or by increasing the rate of
inactivation of vitamin D in the liver (6).

Which begs the question, what was the cereal and fiber intake of the people in Hawaii? and Nebraska?

High of course. So we can't conclude that the levels found in these people reflected only genetic regulation of VT-D.

1. MacAuliffe T, Pietraszek A, McGinnis J: Variable rachitogenic effects of grain and alleviation by extraction or supplementation with
vitamin D, fat and antibiotics. Poultry Sci 1976;55:2142-47.
2. Hidiroglou M, Ivan M, Proulx JG, Lessard JR: Effect of a single intramuscular dose of vitamin D on concentrations of liposoluble
vitamins in the plasma of heifers winter-fed oat silage, grass silage or hay. Can J Anim Sci 1980;60:311-18.
3. Sly MR, van der Walt WH, Du Bruyn DB, Pettifor JM, Marie PJ: Exacerbation of rickets and osteomalacia by maize: a study of bone
histomorphometry and composition in young baboons. Calcif Tissue Int 1984;36:370-79.
4. Batchelor AJ, Compston JE: Reduced plasma half-life of radio-labelled 25-hydroxyvitamin D3 in subjects receiving a high fiber diet.
Brit J Nutr 1983;49:213-16.
5. Clements MR, Johnson L, Fraser DR: A new mechanism for induced vitamin D deficiency in calcium deprivation. Nature

Don said...

@Ken again,

Peter's conclusion that only fatty fish supply substantial vitamin D is marred by reliance on data collected on animal products from animals raised in confinement operations. Calf liver is a particularly poor example since calves are raised for veal in a way that would prevent the animal from producing any vitamin D. An animal spending its time grazing outdoors will produce D and store it in liver and fatty tissues. You need assays of vitamin D on strictly pastured or wild animals to substantiate your suggestion that previous generations could not have gotten much D from foods. Dr. Weston Price found that foods of preagricultural tribes supplied substantial amounts of D (Nutrition and Physical Degeneration).

Regarding calcification side-effects of high D levels, these may be signs of inadequate vitamin K-2 in relation to vitamin D. People used to eat the meats, fats, and organs of grass fed animals which contains substantial amounts of K-2, particularly liver, and K-2 prevents pathological calcification.

I will agree that heliophobia appears expressed more often historically than heliophilia. However, this may ignore context. The sun avoidance Peter noted occurred among people who had substantial indirect and direct sun exposure in outdoor work. Peter says "they avoided the sun as much as possible." Maybe so, but how much avoidance is possible when you have outdoor work to do every day?

Above this claim Peter quoted the Harinarayan study : “agricultural workers starting their day at 0800 and working outdoors until 1700 with their face, chest, back, legs, arms, and forearms exposed to sunlight.” That's nine hours in the sun, through the mid-day, with much skin exposed. They might prefer to avoid the sun when possible, but the nature of their work forced exposure on a regular basis.

Which reminds me that in many cultures pale skin due to sun avoidance has been associated with wealth--not needing to do physical labor in the fields.

My experience also suggests people variably express heliophobia or heliophilia depending on their environment and season. I lived in Seattle for 7 years, during which I would say most people exhibited heliophilia -- we didn't have many sunny days, but when we did, people by and large wanted to be outside to enjoy it. Now I live in Phoenix, AZ, and by and large people exhibit more heliophobia.

I grew up in northern Ohio. By the end of the winter, most people would be complaining about the long dark months and when the brighter days arrived during the winter or in spring, many would exhibit heliophilic behavior. However, after a few months of sun, people would exhibit heliophobic behavior in the middle of the summer.

Ken said...

OK I'll admit overstating things in my previous comment.

The main problem I have with raising levels by supplementation is that a mechanism has evolved to prevent toxicity though sun exposure, that is not the case for ingesting vitamin D.

From that I infer that excess vitamin D from synthesis in the skin was a danger; UV is everywhere strong enough for all humans to have retained the original African system of 'D' limitation.

It is maybe true that wild animals have more vitamin D; that's still not saying much. The amount available from food never approached the massive excess potentially available from the sun. Although food is a source of 'D' it's evident the possibility of vitamin D poisoning from eating wild animals never existed; humans never evolved a mechanism to guard against it.(Ref.1)

Most people on this study are going to be raising their serum concentration to attain the putative 'sufficiency'. Raising levels requires ingesting vitamin D in evolutionarily unprecedented amounts; what the the long term effects are is still to be established.

Seattle - like Nebraska - is below the latitude that the ancestors of most of its people evolved at. I don't see how they can be suffering low vitamin D levels.

Peter Frost's assertion that sun avoidance - to the extent compatible with farm work - is the norm in traditional societies shows a kind of 'primal wisdom' in those living closer to nature. Paleolithic hunters may not have actively avoided the sun but I doubt their traditions encouraged sunbathing.

Most of those we know about had folkways compatible with a less is more attitude to the sun. Unless they were all deluded a little sun goes a long way (vitamin d is also made in shade).

Pre- agricultural ancestors of Europeans who ate the most meat are something Peter has a hypothesis about, one that you may find interesting.
P.4- hunting bands of the continental Arctic.

1)Vieth says " Fraser (1983) has
argued that dermal absorption of vitamin D may be more natural, (but) what we know from animals indicates that oral consumption is equally physiological. Since vitamin D can be extracted from UV-exposed human sweat and skin secretions (Bicknell and Prescott,
1946), it is also reasonable to think that early humans obtained some of their vitamin D by mouth as well, by licking the skin."
( Vieth P.7)

Don said...


Thanks for your comments. I disagree with several of your points but my response takes more characters than allowed in a comment.

These Indonesian whale hunters don't appear to avoid the sun-- they're 'half naked' during the hunt.


The Grassroots project scientists are suggesting only 2000 IU per day, which is far below the 10K we can produce in 20-40 minutes to minimal erythmal dose, and the potential 240K that would be produced over 8 hours if we had no limiting system. I haven't seen anyone recommending doses above 5K.

And some hunters may have consumed this amount orally. A 3.5 ounce serving of wild salmon contains 500-1000 IU of D and about 200 kcal.(1)

10 servings (35 ounces) would supply only 2000 kcal (two thirds the requirement of an active young male) and 5K to 10K of vitamin D. Hunters of the Arctic and Pacific Northwest also liberally consumed oils of fish, seal, and whale, all of which contain D as well. So it appears they could have easily consumed 2K daily, and I would disagree that this dose is evolutionarily unprecedented. I would like to see any evidence that hunters of the Arctic or Pac NW or northern Europe (cod) suffered from toxicity of orally ingested vitamin D.

1. Lu Z, Chen TC, Zhang A, Persons KS, Kohn N, Berkowitz R, Martinello S, Holick MF. An evaluation of the vitamin D(3) content in fish: Is the vitamin D content adequate to satisfy the dietary requirement for vitamin D? J Steroid Biochem Mol Biol. 2007 Jan 29; [Epub ahead of print] doi:10.1016/j.jsbmb.2006.12.010