What is Vitamin D?
Vitamin D is actually a hormone, and not a vitamin, although for some reason, it is referred to as a vitamin (McDougall p. 158). Humans produce Vitamin D from sun exposure, not from foods, although some “food” items, such as calcium pills and dairy foods, have Vitamin D added, one would not be consuming those on a vegan or vegan raw foods diet [and, McDougall doesn’t recommend either of those options].
Blood levels of Vitamin D – are they accurate?
There has been a lot of media hype in the last year or two regarding Vitamin D and how many Americans are deficient in this vitamin, and that supplementation has been suggested and/or sunbathing for about 30 minutes to an hour each day [one author who recommends the sunbathing option is Swazye Foster in her new book The Science of Raw]. I had heard some about this media hype from different sources, but I tended not to pay too much attention to media hype in general as these kinds of things tend to be more along the lines of ‘fads’ rather than sound medical advice or evidence-based information; often the media stories about such things tend to be based on one or two studies, which may or may not have been done well.
Then, about a year and a half ago, I had my Vitamin D level [among other things] checked [with blood chemistries], and my Vitamin D level was reported to be below suggested levels. Even though I live in Hawaii and I tend to spend roughly 16 to 20 hours outdoors [although usually just my arms are exposed to the sun], my Vitamin D level was considered low. McDougall reports on two research studies testing the Vitamin D levels of people living in Hawaii with average sun exposure of 29 hours per week in one study [the other study didn’t mention exposure time], between 44% and 51% of the research participants had blood levels of Vitamin D below what is considered acceptable. If people in Hawaii don’t tend to have ‘normal’ blood levels of Vitamin D and they spend quite a few hours exposed to the sun, what does this mean? We’ll look at this in more detail.
My doctor, who does not recommend such things lightly, suggested taking a Vitamin D oil supplement, which I did. I have been taking the recommended amount of Vitamin D oil for over a year and a half now. Unfortunately, I haven’t had my level checked recently, so I don’t know if my blood level of Vitamin D has been positively affected by supplementation. Also, some researchers believe that the level reported to be ‘normal’ for Vitamin D in blood tests may currently be too high. For example, according to McDougall, the current standard or level for Vitamin D for normal values [as of the publication of his book in 2012] is 30 to 80 ng/ml. McDougall believes, however, that 20 ng/ml is adequate, based on several studies he cites. Due to these and other factors, I am now re-thinking supplementation of this vitamin after reading three well-researched and documented books: The China Study by Campbell and Campbell, Whole by Campbell and The Starch Solution by McDougall and McDougall.
One of the problems with suggesting supplementation [as I’ve noted in earlier articles] is that it is based on ‘reductionist science’ – meaning that researchers focus on one component of a food or a nutrient at the expense of all others. This has been done with many nutrients: Vitamin E, Vitamin B, Selenium, Vitamin C, and many others. I’ll write an article on Vitamin E later, but after reading Whole, I discovered that the original research studies suggesting that Vitamin E supplementation might help reduce heart attacks was flawed, and, furthermore, later research found that Vitamin E supplementation might actually increase heart attacks! As Campbell and Campbell discuss in The China Study, the mechanisms and metabolism of various nutrients in our bodies is complex, and often by studying only one component of a nutrient, the complexities are not taken into account and the effects of the one nutrient may be exaggerated or lost in translation of the details or complexities. Campbell and Campbell note that Vitamin D IS affected by the foods we eat, but not in the way that other vitamins are. They describe how certain ‘foods’ can cause Vitamin D to be suppressed, and that these ‘foods’ turn out to be animal proteins, as well as excessive calcium [like enhanced dairy products] (p. 180-81). [Not only is Vitamin D affected by animal protein and dairy intake, but so is calcium; dairy products tend to leach calcium out of bones; more on that later!] Campbell and Campbell remind us that Vitamin D formation in the body, like all other nutrients, is a complex web of coordinated chemical and biological reactions; “a multitude of reactions working together in so many ways” (p. 181). McDougall further reinforces that the media hype of the lack of Vitamin D in so many Americans, especially those living farthest from the equator, are at greater risk for common diseases such as heart disease, stroke, type 2 diabetes, common cancers, and multiple sclerosis (p. 160). However, a very important fact is missed with all the hype about low Vitamin D levels: “as people move farther from the equator, they eat fewer plant foods and more animal foods. Sunshine plays a big part in overall health, but a small part in the prevention of common Western diseases. Vitamin D supplements will not cure these diseases” (p. 160).
What is best way to get enough Vitamin D?
So, depending on whether you choose to follow the current normal levels of Vitamin D, or choose to follow McDougall’s recommendation of 20 ng/dl, what might you do if your level is even below the 20 ng/dl?
First, McDougall suggests that if your level is found to be below 20 ng/dl, he would have it re-tested to be sure there was no lab error. If it is still under 20 after the re-test, he recommends spending more time in the sun and test again before taking Vitamin D supplementation, which he thinks could even be dangerous! Second, if it is difficult to spend extra time in the sun, McDougall recommends tanning beds; he thinks they are the second best methods to boost Vitamin D. So, if you live in an area where getting enough sunlight to improve your Vitamin D levels, then spend an appropriate amount of time, similar to the time recommended to be outdoors, in a tanning bed – but don’t overdo it! As McDougall notes, “when used appropriately, like sunshine, tanning beds can safely prevent or reverse Vitamin D deficiency” (p. 162). Supplementation, he believes, is the choice of last resort, as it can lead to imbalances, and may actually hurt bones. McDougall notes that a “major research article in the May 2010 Journal of American Medical Association showed that a large dose of Vitamin D given to elderly women result in more falls and 26% more fractures than in women taking a placebo” (p. 162-3). Thus, Vitamin D supplementation may actually be a contraindication for some, and this needs to be studied more.
In conclusion, according to experts, exposing yourself to the sun every couple of days for up to an hour or so is recommended to maintain appropriate Vitamin D levels. If this isn’t possible, a tanning bed is a second option. Supplementation may be a last resort, but it may also lead to problems. So, get out in the sun and enjoy the outdoors! :)