The 4-Hour Body_ An Uncommon Guide to Ra - Timothy Ferriss [210]
It has also been hypothesized that vitamin D toxicity is often a result of vitamin K deficiency. If you choose to supplement with vitamins A and D, as I do with cod liver oil and liquid vitamin D, it is important to ensure adequate K(2). Suggested sources include butter from grass-fed cows and the aforementioned lacto-fermented foods.
In practice, and as a personal example, this just means I have a few forkfuls of kimchi or sauerkraut in the morning while I wait for my scrambled eggs9 to cook in—what else?—butter from grass-fed cows. Easy peazy.
VITAMIN D3—6,000–10,000 IU PER DAY FOR FOUR WEEKS
One of the top sports scientists in the United States, who wished to remain anonymous, recounted a single anecdote that led me to a closer reexamination of vitamin D:
One NFL player I ended up treating had experienced debilitating shoulder pain for years and had two surgeries as a result, all to little or no effect. Upon testing his vitamin D levels, it became clear that he was severely deficient. Six weeks after taking vitamin D, his shoulder pain was nonexistent. He had two surgeries for no reason.
Vitamin D, it turns out, does a lot more than most vitamins.
Once vitamin D is activated within the body as calcitriol, it acts as a steroid hormone and regulates more than 1,000 vitamin D–responsive genes, including those that code for specific muscle fibers. It can increase the size and number of type 2 (fast-twitch) fibers, which, as indicated earlier, have the greatest potential for growth. It is one of the most overlooked “sleeper nutrients,” according to John Anderson, professor emeritus of nutrition at the University of North Carolina.
The effect can be substantial. Even at just 1,000 IU10 daily for two years, 48 elderly females deficient in vitamin D (as I was) tripled their percentage of fast-twitch muscle fibers and doubled fiber diameter in functional limbs. The control group experienced no gains.
Peak athletic performance appears to begin when blood levels approach those obtained through persistent full-body exposure to natural summer sun: 50 ng/ml.
Do you think you get enough sun? It’s unlikely. Even in the endless summer of subtropical Miami, a surprisingly high incidence of vitamin D deficiency has been recorded, as most people either use sunblock or avoid prolonged sun exposure. Forty percent of Louisiana-based runners tested in another study, all of whom trained outdoors, registered insufficient vitamin D levels. Indoor workers and athletes are top candidates for major insufficiencies: Lovell and collaborators found 15 of 18 elite female gymnasts tested to have levels below 30 ng/ml, and 6 to have levels below 20 ng/ml.
Simple at-home tests (see the resources listed in the “Getting Tested” appendix) can tell you where you are, and consistent UV-B or sun exposure (20–30 minutes at least twice per week, depending on latitude), along with sublingual D3, can get you to our minimal target of 50 ng/ml. More than 100 ng/ml is considered excessive, and more than 150 ng/ml is considered toxic.
If you don’t get tested and blindly take vitamin D, you run the risk of overdose. One mild overdose symptom can be a metallic taste in the mouth, which Neil from “Occam’s Protocol” experienced. In our rush to start the program, and based on the average deficiencies I’d seen in the blood reports of past subjects, we neglected to get his vitamin D tested. I didn’t realize that he surfed for several hours a day.
Establish your baseline first.
My Experience
Baseline from first blood test: 32 ng/ml
Second test on 8/20/09 (after two months of taking 1,000 IU/day and 20 minutes of sun exposure daily): 35 ng
Third test 5 weeks later on 9/25/09 (after increasing intake to 7,200 IU/day): 59 ng/ml
I split the 7,200 IU into two doses: 1.5 droppers full of Now® liquid vitamin D3 upon waking and again before bed. It’s important to test droppers, rather than trust label claims: even though the bottle claims 5,000 IU per dropperful, the average dropper yield was just 24 drops and 4 drops is 400 IU, so the