Michael Matthews Bigger Leaner Stronger The Simple Science of Building the Ultimate Male Body.pdf

Vitamin d just a few years ago vitamin d was simply

Info icon This preview shows pages 276–278. Sign up to view the full content.

VITAMIN D Just a few years ago, vitamin D was simply known as the “bone vitamin,” and even today, many physicians still believe it is essential only for bone health. Research shows otherwise, however: insufficient vitamin D levels increase the risk of many types of disease, including osteoporosis, heart disease, stroke, some cancers, type 1 diabetes, multiple sclerosis, tuberculosis, and even the flu, but we’re going to focus on the positive. 1 Thanks to the hard work of many scientists, including the notable Dr. Michael Holick, we now know that nearly every type of tissue and cell in the body has vitamin D receptors, which means it’s an essential hormone that plays a vital role in
Image of page 276

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

a large number of physiological processes. 2 When we ingest vitamin D or produce it in the skin (as a result of sun exposure), it gets converted into its active form, 1,25-dihydroxyvitamin D, or vitamin D3. 3 This substance then interacts with and supports virtually every tissue type in your body, including your heart, brain, and even fat cells. It also regulates genes that control immune function, metabolism, and cell growth and development. 4 As you can see, this vitamin deserves a lot more attention than it has been given over the last couple of decades. Fortunately, however, vitamin D’s vital importance and amazing benefits are becoming more and more widely known and accepted. Now, as you may already know, our body can’t produce vitamin D without sun exposure, and according to research published by the Center for Disease Control in 2011, 8 percent of Americans are vitamin D deficient, and 25 percent are considered “at risk” of a deficiency. 5 According to other research, however, deficiency may be as high as 42 percent. 6 There are two ways to ensure you get enough vitamin D: 1. Spend 15 to 20 minutes in the sun every day with at least 25 percent of your skin exposed. 7 2. Take supplements. As most of us aren’t able to take midday tanning breaks, supplementation is the answer. H OW TO T AKE V ITAMIN D According to the Institute of Medicine, 600 IU per day is adequate for ages 1 to 70 (and 800 IU per day for 70+), 8 but these numbers have been severely criticized by scientists who specialize in vitamin D research. 9 They call attention to the over 125 peer-reviewed studies that indicate such recommendations are too low and are likely to lead to vitamin D deficiencies. A committee of the U.S. Endocrine Society recently convened to review the evidence and concluded that between 600 and 1,000 IU per day is adequate for ages 1 to 18, and between 1,500 and 2,000 IU per day is adequate for ages 19+. 10 According to Dr. Michael Holick, however, even 2,000 IU per day is suboptimal. Research shows that 2,000 IU per day is the minimum needed to maintain vitamin D sufficiency (30 milligrams per milliliter), but Dr. Holick maintains that optimal vitamin D status is between 50 and 80 milligrams per milliliter, which would call for a daily intake closer to 5,000 IU.
Image of page 277
Image of page 278
This is the end of the preview. Sign up to access the rest of the document.
  • Winter '17
  • Santos O'Neill Garcia
  • History

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern