CrossFit Discussion Board  

Go Back   CrossFit Discussion Board > CrossFit Forum > Nutrition
CrossFit Home Forum Site Rules CrossFit FAQ Search Today's Posts Mark Forums Read

Nutrition Diet, supplements, weightloss, health & longevity

Reply
 
Thread Tools
Old 03-30-2010, 05:06 AM   #1
Juho Haapakangas
Member Juho Haapakangas is offline
 
Profile:
Join Date: Jan 2010
Location: Oulu  Finland
Posts: 10
Study: vitamin D increases testosterone levels

If this has been posted before feel free to delete/move this thread.

I ran into this study (December, 2009) that found a correlation between vitamin D- levels and amount of testosterone.

Here is the summary, there's a link to the full article:
http://www3.interscience.wiley.com/j...27538/abstract (WFS)

From what I understood:
- The researchers routinely measured the amount of vitamin D, testosterone, free androgen and SHBG (Sex hormone-binding globulin) in 2299 men through 1997-2000
- Men who had sufficient vitamin D levels had significantly higher testosterone and free androgen index and lower SHBG levels
- Some of the men were using their own vitamin supplementation which included vitamin D, but their testosterone levels were only slighly higher than normal
- Testosterone and androgen levels showed a strong seasonal correlation. The levels were lowest in March and highest in August.
- Of the participants 11.4 % were sufficient, 25.6 % insufficient, 43 % moderately deficient and 19.9 % serevely deficient in vitamin D levels
- 18 % had hypogonadism (very low testosterone), their vitamin D levels were significantly lower than mean values
- In the introduction-chapter the researchers state that vitamin D is mainly produced in the skin and nutrition/supplementation only plays a minor role (this statement is quoted from a previous study which I have not read)

Testosterone enhances muscle development, strength, and endurance. Is increased testosterone the reason vitamin D improves performance (or performance is increased in the summer)?
  Reply With Quote
Old 03-30-2010, 01:33 PM   #2
David Meverden
Member David Meverden is offline
 
David Meverden's Avatar
 
Profile:
Join Date: Apr 2008
Location: Charleston  SC
Posts: 2,802
Re: Study: vitamin D increases testosterone levels

It sounds like they mainly found correlation, not causation.

In other words, testosterone and Vitamin D levels may be associated, but that's not the same thing finding that vitamin D supplementation will cause higher testosterone levels, especially with a statement like the following: "Some of the men were using their own vitamin supplementation which included vitamin D, but their testosterone levels were only slighly higher than normal"

Still, interesting stuff (and yet ANOTHER reason that whole milk, which contains fat soluble vitamin D that is readily absorbed, may be better than steroids for novices, haha). Thanks for posting it. I hope this spurs more, similar, research.
  Reply With Quote
Old 03-30-2010, 03:37 PM   #3
Adam Acosta
Member Adam Acosta is offline
 
Profile:
Join Date: Apr 2007
Location: Whittier  CA
Posts: 243
Re: Study: vitamin D increases testosterone levels

I remember reading Michael Rutherford saying something to the effect of coaches noticing and taking advantage of athletes making greater strength gains in the summer than otherwise when planning a periodized training schedule.
  Reply With Quote
Old 03-30-2010, 04:33 PM   #4
Katherine Derbyshire
Member Katherine Derbyshire is offline
 
Profile:
Join Date: Jan 2009
Location: Seattle  WA
Posts: 7,596
Re: Study: vitamin D increases testosterone levels

Quote:
Originally Posted by Adam Acosta View Post
I remember reading Michael Rutherford saying something to the effect of coaches noticing and taking advantage of athletes making greater strength gains in the summer than otherwise when planning a periodized training schedule.
Remember that high school and college athletes don't have classes in the summer, which presumably allows them to focus on their training more.

Katherine
  Reply With Quote
Old 03-30-2010, 04:38 PM   #5
Wayne Riddle
Member Wayne Riddle is offline
 
Profile:
Join Date: Jul 2009
Location: Lewiston  ME
Posts: 1,779
Re: Study: vitamin D increases testosterone levels

Quote:
Originally Posted by Adam Acosta View Post
I remember reading Michael Rutherford saying something to the effect of coaches noticing and taking advantage of athletes making greater strength gains in the summer than otherwise when planning a periodized training schedule.
I recall reading (think on Dr. Harris's blog) that you need a certain level of vitamin d to maximize muscle strength.
  Reply With Quote
Old 03-30-2010, 06:03 PM   #6
Steven Low
Member Steven Low is offline
 
Steven Low's Avatar
 
Profile:
Join Date: Sep 2005
Location: silver spring  maryland
Posts: 12,221
Re: Study: vitamin D increases testosterone levels

Quote:
Originally Posted by Wayne Riddle View Post
I recall reading (think on Dr. Harris's blog) that you need a certain level of vitamin d to maximize muscle strength.
You may recall reading that in my article as well.

Russians found it to be approximately 50 ng/mL in the blood. More or less confirmed by everything else.

Remember, vitamin D is a seco-steroid so it does have muscle hypertrophy and strength-like effects associated with higher intake (within normal limits of course).

I described some of the effects in part 4 of the said article. Refresher if you want wfs

http://www.eatmoveimprove.com/2009/1...-at-vitamin-d/
__________________
Posts are NOT medical, training, nutrition info
Bodyweight Article, Overcoming Gravity Book
  Reply With Quote
Old 03-31-2010, 02:35 AM   #7
Wayne Riddle
Member Wayne Riddle is offline
 
Profile:
Join Date: Jul 2009
Location: Lewiston  ME
Posts: 1,779
Re: Study: vitamin D increases testosterone levels

Quote:
Originally Posted by Steven Low View Post
You may recall reading that in my article as well.
Probably as I've read your article a few times.
  Reply With Quote
Old 03-31-2010, 06:18 AM   #8
Steven Low
Member Steven Low is offline
 
Steven Low's Avatar
 
Profile:
Join Date: Sep 2005
Location: silver spring  maryland
Posts: 12,221
Re: Study: vitamin D increases testosterone levels

Quote:
Originally Posted by Wayne Riddle View Post
Probably as I've read your article a few times.
I actually probably need to do some rewriting of half of my articles now though, gah.
__________________
Posts are NOT medical, training, nutrition info
Bodyweight Article, Overcoming Gravity Book
  Reply With Quote
Reply


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Soy Protein Powder and Testosterone Levels William Reese Nutrition 1 01-01-2009 05:59 PM
Sleep Quantity Affects Morning Testosterone Levels In Older Men Kevin McKay Injuries 0 04-03-2007 03:52 PM
Effect of meal fat content on salivary testosterone and cortisol levels in healthy female volunteers Jibreel Freeland Nutrition 0 08-29-2006 09:39 PM
Low Testosterone Levels Associated With Increased Risk Of Death In Men Kevin McKay Injuries 1 08-17-2006 08:44 AM
Testosterone levels Marty Fitness 1 12-10-2005 10:59 AM


All times are GMT -7. The time now is 08:22 AM.


Powered by vBulletin® Version 3.6.8
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
CrossFit is a registered trademark of CrossFit Inc.