Nutrition Testing Part 2: Vitamin D Testing for Optimal Health and Athletic Performance
In the video above, you can watch me do my first Vitamin D test. Yes, I am a huge pussy and I HATE needles, even though the needles used (as I found out) are really really small. Stay tuned to this article, as I will reveal how you can get your levels tested for better than free–they may pay YOU to have it done. Read on….
Vitamin D and D is for Defficiency
I am sure you have heard of Vitamin D by now, and for good reason. Currently there is an epidemic of low Vitamin D level almost everywhere!
Just like Omega 3 status, it is critical to know your Vit D status, especially if you live in a more northern climate. Even if you are not, there is a good chance that you are low since many people in states like Arizona, Texas, etc do not go outside much during the day since it is so hot!
At the ISSN conference I went to a great presentation on the vitamin D and the presenter (Rikki Keen) has tested athletes from all over and has found that even track athletes in FL were low, since due to heat, most of their practices were later in the day when the rays from the sun were too low to allow sufficient vitamin D production.
8 Time Olympian Ronnie Coleman
Vitamin D is a group of fat-soluble “steroid.” Yes a steroid! Aaaaah. Call the FDA right now.
This is using the formal classification of the term steroid as cholesterol is technically a steroid too. These compounds are naturally occurring in the body and different from anabolic steroids that athletes may use (which are illegal here in the US unless under supervision for hormone replacement under a physician).
The two major forms of which are vitamin D2 (also known as ergocalciferol) and vitamin D3 (known as cholecalciferol). Vitamin D3 is produced in the skin after exposure to ultraviolet B light from the sun or artificial sources. Ultraviolet A (UVA) does not seem to raise vitamin D levels.
We can get some from food sources such as milk, fatty fish like salmon, cod liver oil, and a few other foods that are artificially fortified with vitamin D.
The sun is still the best source, and it is also available as a supplement in pill form. If you supplement, the D3 form is going to be best and is also very cheap.
What Is Optimal?
From the Vitamin D Council’s website, it states
“25(OH)D levels should be between 50–80 ng/ml (125–200 nmol/L), year-round.”
Vitamin D is measured by 25(OH)D levels and can be done by a simple blood test as shown in my video above.
When you go in for your physical, you can request a Vitamin D test and most of the time your insurance will pay for it (check to make sure). Make sure it is the 25(OH)D test though NOT 1-25(OH)D test. As Rikki Keen pointed out in her presentation at the ISSN in FL recently, she stated that there still are some docs that will request the wrong test. She writes it down for her clients and has them bring in the piece of paper to give to them to make sure they get it right.
A Better Than FREE Test?
If you order the test from the Vitamin D Council’s website, it is a few buck cheaper and you may be able to get paid to get your levels checked!
Check out these links
Is Vitamin D Toxic?
I was at the American College of Sports Medicine (ACSM) Annual conference last year and did a short interview with Dr. John Cannell of the Vitamin D council. Check it out.
“Water is more toxic than Vitamin D” -Dr John Cannell
Part 2 Coming Soon?
If people are interested in more info on vitamin D, drop a comment below and in part 2 I will tell you
- What my levels of Vitamin D were
- How much I needed to increase them into a normal range (the answer will surprise you)
- Common doses/types of Vitamin D used
- I need 15 comments by this Sunday at 7pm EST (as I will be gone helping with the Movement Certification here in Minnesota until then)
What do I do now?
Get your vitamin D levels tested via a lab or your doc’s office
Leave a comment below if you want to see part 2
15 comments by this Sunday at 7pm EST for part 2
J Steroid Biochem Mol Biol. 2010 Jul;121(1-2):334-7. Epub 2010 Mar 16.
Sun exposure questionnaire predicts circulating 25-hydroxyvitamin D concentrations in Caucasian hospital workers in southern Italy.
Hanwell HE, Vieth R, Cole DE, Scillitani A, Modoni S, Frusciante V, Ritrovato G, Chiodini I, Minisola S, Carnevale V.
Department of Nutritional Sciences, University of Toronto, Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5. email@example.com
INTRODUCTION: Recent sun exposure should correlate with circulating 25-hydroxyvitamin D [25(OH)D] due to ultraviolet B (UVB)-catalyzed cutaneous synthesis of vitamin D. METHODS: A Sun Exposure Score was calculated for healthy adults using a recall questionnaire assessing daily Time in Sun (<5 min, 5-30 min, >30 min) and Skin Exposure (face/hands; face/hands and arms; face/hands and legs; and “bathing suit”) for 1 week in each of the winter and summer (n=47 and 23, respectively; n=18 participated in both). Concentrations of 25(OH)D were measured by DiaSorin RIA on end-of-week sera. RESULTS: Mean serum 25(OH)D was higher in summer than winter (58.6+/-16.5 nmol/L vs. 38.8+/-29.0 nmol/L, respectively, P=0.003 unpaired). The calculated Sun Exposure Score correlated strongly with serum 25(OH)D during summer (Spearman’s rho=0.59, P=0.003); based on the Pearson coefficient of determination, summer Sun Exposure Score explained 38% of the variability in summer serum 25(OH)D. The Sun Exposure Score did not correlate with 25(OH)D in the winter (rho=0.19, P=0.210). The summer correlation was largely explained by the Time in Sun (rho=0.58, P=0.004) rather than area of Skin Exposed (rho=0.10, P=0.660). Although there was a correlation between winter and summer Sun Exposure Scores (rho=0.63, P=0.005), there was no summer vs. winter correlation in serum 25(OH)D (rho=0.08, P=0.76). CONCLUSION: This simple 1-week sun exposure recall questionnaire predicted summer serum 25(OH)D concentrations, accounting for 38% of the variability in 25(OH)D among healthy Italian adults. Copyright (c) 2010 Elsevier Ltd. All rights reserved.
Diabetes Care. 2010 Jun;33(6):1379-81. Epub 2010 Mar 9.
Association of vitamin D with insulin resistance and beta-cell dysfunction in subjects at risk for type 2 diabetes.
Kayaniyil S, Vieth R, Retnakaran R, Knight JA, Qi Y, Gerstein HC, Perkins BA, Harris SB, Zinman B, Hanley AJ.
Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada.
Diabetes Care. 2010 Jul;33(7):e99; author reply e100.
OBJECTIVE: To examine cross-sectional associations of serum vitamin D [25-hydroxyvitamin D, 25(OH)D] concentration with insulin resistance (IR) and beta-cell dysfunction in 712 subjects at risk for type 2 diabetes. RESEARCH DESIGN AND METHODS: Serum 25(OH)D was determined using a chemiluminescence immunoassay. Insulin sensitivity/resistance were measured using the Matsuda insulin sensitivity index for oral glucose tolerance tests (IS(OGTT)) and homeostasis model assessment of insulin resistance HOMA-IR. beta-Cell function was determined using both the insulinogenic index (IGI) divided by HOMA-IR (IGI/IR) and the insulin secretion sensitivity index-2 (ISSI-2). RESULTS Linear regression analyses indicated independent associations of 25(OH)D with IS(OGTT) and HOMA-IR (beta = 0.004, P = 0.0003, and beta = -0.003, P = 0.0072, respectively) and with IGI/IR and ISSI-2 (beta = 0.004, P = 0.0286, and beta = 0.003, P = 0.0011, respectively) after adjusting for sociodemographics, physical activity, supplement use, parathyroid hormone, and BMI. CONCLUSIONS: Vitamin D may play a role in the pathogenesis of type 2 diabetes, as 25(OH)D concentration was independently associated with both insulin sensitivity and beta-cell function among individuals at risk of type 2 diabetes.
Pediatr Clin North Am. 2010 Jun;57(3):849-61.
Vitamin D, muscle function, and exercise performance.
Bartoszewska M, Kamboj M, Patel DR.
Michigan State University College of Human Medicine, East Lansing, MI, USA.
Vitamin D has an important role in skeletal muscles. Previously recognized for its effects on bone, it is now known that vitamin D has a much wider spectrum of usefulness for muscle. Studies indicate that vitamin D deficiency is pandemic. Those affected include the young and otherwise healthy members of the population, including athletes. Controversy exists regarding the amount of supplementation required to reverse deficiency and the relative effect of such a reversal on overall health. This article reviews current data on the role of vitamin D on muscle function, and explores the potential implications of its deficiency and supplementation on physical fitness and athletic performance.
Scand J Med Sci Sports. 2010 Apr;20(2):182-90. Epub 2009 Oct 5.
Vitamin D and human skeletal muscle.
ASPETAR, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar. firstname.lastname@example.org
Vitamin D deficiency is an increasingly described phenomenon worldwide, with well-known impacts on calcium metabolism and bone health. Vitamin D has also been associated with chronic health problems such as bowel and colonic cancer, arthritis, diabetes and cardiovascular disease. In recent decades, there has been increased awareness of the impact of vitamin D on muscle morphology and function, but this is not well recognized in the Sports Medicine literature. In the early 20th century, athletes and coaches felt that ultraviolet rays had a positive impact on athletic performance, and increasingly, evidence is accumulating to support this view. Both cross-sectional and longitudinal studies allude to a functional role for vitamin D in muscle and more recently the discovery of the vitamin D receptor in muscle tissue provides a mechanistic understanding of the function of vitamin D within muscle. The identification of broad genomic and non-genomic roles for vitamin D within skeletal muscle has highlighted the potential impact vitamin D deficiency may have on both under-performance and the risk of injury in athletes. This review describes the current understanding of the role vitamin D plays within skeletal muscle tissue.
Curr Opin Clin Nutr Metab Care. 2009 Nov;12(6):628-33.
Vitamin D and its role in skeletal muscle.
Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, MA 02111, USA. email@example.com
PURPOSE OF REVIEW: Vitamin D is best known for its role in regulating calcium homeostasis and in strengthening bone. However, it has become increasingly clear that it also has important beneficial effects beyond the skeleton, including muscle. This review summarizes current knowledge about the role of vitamin D in skeletal muscle tissue and physical performance. RECENT FINDINGS: Molecular mechanisms of vitamin D action in muscle tissue include genomic and nongenomic effects via a receptor present in muscle cells. Knockout mouse models of the vitamin D receptor provide insight into understanding the direct effects of vitamin D on muscle tissue. Vitamin D status is positively associated with physical performance and inversely associated with risk of falling. Vitamin D supplementation has been shown to improve tests of muscle performance, reduce falls, and possibly impact on muscle fiber composition and morphology in vitamin D deficient older adults. SUMMARY: Further studies are needed to fully characterize the underlying mechanisms of vitamin D action in human muscle tissue, to understand how these actions translate into changes in muscle cell morphology and improvements in physical performance, and to define the 25-hydroxyvitamin D level at which to achieve these beneficial effects in muscle.