Study: Vitamin D and strength

[BazingaO]

Juste read this study and I wanted to share it with you, if it hasn't already been posted. Don't know if it's relevant or not but I found this to be interesting.

Vitamin D supplementation increases upper and lower limb strength. Further research should focus on its effect on muscle power, endurance and maximal strength.

It doesn't mention the level of the subjects though, only their age. And note that the dose of Vitamin D should be at least 4000 IU daily, but I don't know what it represents.

Source: http://www.ncbi.nlm.nih.gov/pubmed/25156880


So now my question is, should I look into eating more foods that contain Vitamin D?
Or are we getting more than enough with a regular diet that is composed of a variety of whole and minimally processed foods?

[Mrpb]

Depends on your diet. Look up vitamin D sources.

I started supplementing after reading the study.

It seems as vitamin D boosts my energy. Maybe I was deficient.

[MichielN]

Vit D intake doesn't mean much, not everybody needs the same amount. What matters is your serum 25[OH]D levels, which should be between 40 and 50 ng/dl (or 100 and 125 nmol/l). So really you should get a blood test done to figure out where you're at, and adjust your intake accordingly.

On average though, I'd say most people need somewhere between 2.000 and 5.000 IU per day. You cannot get this from food, in most cases a supplement is beneficial.

[Follix]

Wouldn't sunlight be the best vitamin D source?

I know that's not possible for everyone, especially during those months...

[BazingaO]

Wouldn't sunlight be the best vitamin D source?

I know that's not possible for everyone, especially during those months...

Actually I read that your body can produce 15000IU (vitamin D) if exposed for 15 minutes at a summer sun.
So yes it's a very good source, but only for some.

Otherwise, beef liver, some mushrooms and orange are a great source too.

[cls91]

So now my question is, should I look into eating more foods that contain Vitamin D?
Or are we getting more than enough with a regular diet that is composed of a variety of whole and minimally processed foods?

Like Mrpb said, look at your diet vs. food sources of Vitamin D. If you haven't already done so, I think you'll be very surprised how limited it is in whole foods. Without considering fortified foods, if you're not eating salmon on a regular basis, you're likely not getting enough... and even if you are eating salmon on a regular basis, you're still probably not getting enough lol

Sources of Vit. D: http://www.dietitians.ca/Nutrition-R...Vitamin-D.aspx
Sources of Vit. D:http://whfoods.org/genpage.php?tname=nutrient&dbid=110
(keep in mind the first link is Canadian, not sure how similar it would be to France)

Vit D intake doesn't mean much, not everybody needs the same amount. What matters is your serum 25[OH]D levels, which should be between 40 and 50 ng/dl (or 100 and 125 nmol/l). So really you should get a blood test done to figure out where you're at, and adjust your intake accordingly.

On average though, I'd say most people need somewhere between 2.000 and 5.000 IU per day. You cannot get this from food, in most cases a supplement is beneficial.

Where do you draw those numbers from? I know the RDA isn't always the best recommendation, but 2,000-5,000 IU is quite the jump, and like you said would be very difficult to obtain through diet.

Wouldn't sunlight be the best vitamin D source?

I know that's not possible for everyone, especially during those months...

Actually I read that your body can produce 15000IU (vitamin D) if exposed for 15 minutes at a summer sun.
So yes it's a very good source, but only for some.

Otherwise, beef liver, some mushrooms and orange are a great source too.

There's a couple pages of friendly arguing between me and ilove2run about Vitamin D synthesis and sun exposure in the MMDELAD thread
Starts here: http://forum.bodybuilding.com/showth...post1294890151

There are sources and studies references throughout if either of you are interested in reading through.

Also @Bazinga, AFAIK those aren't good sources of Vitamin D. Beef liver is quite low per kcal meaning it would be unrealistic to use it as a prominent source of your intake; oranges just lack Vit. D in general unless you are talking about fortified orange juice, in which case it's still not that great; and mushrooms are a pretty good source but you'd have to be eating a crapload of mushrooms for any significant amount.

[MichielN]

Where do you draw those numbers from? I know the RDA isn't always the best recommendation, but 2,000-5,000 IU is quite the jump, and like you said would be very difficult to obtain through diet.

Real world observations, for one.

[unstrong]

I started taking 5,000IU of Vitamin D. Definitely think it makes a difference, especially in winter when I'm at work during basically all of the daylight hours.

[Mrpb]

Wouldn't sunlight be the best vitamin D source?

The term 'best' is a bit tricky here, especially when we consider things like skin cancer.

[WonderPug]

FYI: A deficiency in calcidiol can cause myriad problems including decreased strength, which is very different than saying vitamin D supplementation increases limb strength.

[jdfitlaw]

In regards to Vitamin D, it seems like the more research that comes out about it, the more we learn of its value. I currently take 5,000 IU of D3. Not sure if I could go above that or if it has any value to go above that number, but I'm still in the process of reading about proper dosage. Regardless, it appears to be the case that supplementation of Vitamin D is valuable for a wide swath of people. Even my 97-year-old grandmother supplements with it and she has shown an improvement - but I don't expect her to be doing deep squats anytime soon. She is however, kicking the butt (health-wise) of people 10 years younger than herself.

[snorkelman]

I do not go out of my way to supplement Vit D. However, I do supplement Calcium, which includes some Vit D.

The bros in the supp forum seem to love Vit D and supplement it in large amounts. However, excessive amounts may cause a rise in calcium and phosphorous in the blood and excessive excretion of calcium in the urine. This may lead to calcification of soft tissues and of the walls of the blood vessels and kidney tubules, a condition called hypercalcemia. Too much vitamin D for prolonged periods can result in weight loss, headaches, and kidney stones.

[Mrpb]

The bros in the supp forum seem to love Vit D and supplement it in large amounts. However, excessive amounts may cause a rise in calcium and phosphorous in the blood and excessive excretion of calcium in the urine. This may lead to calcification of soft tissues and of the walls of the blood vessels and kidney tubules, a condition called hypercalcemia. Too much vitamin D for prolonged periods can result in weight loss, headaches, and kidney stones.

Interesting. What is still a normal dosage and when does it become excessive?

[MichielN]

Interesting. What is still a normal dosage and when does it become excessive?

Refer to my post, #3.

It's fairly individual as it is a fat-solubable vitamin, and it is primarily stored in adipose tissue. Also things like vitamin A-status matter.

Again, actual intake in IU does not mean anything per se, blood levels are what matter. If they are too high (> 50 ng/dl), you gradually increase your risk for soft tissue calcification etc (which increases your risk of heart disease for example).

[WonderPug]

Interesting. What is still a normal dosage and when does it become excessive?

You don't look for a "dosage". Rather, you supplement if blood levels are too low to cure such.

[Caezar07]

From what I understand, the less sunlight you get, and the darker your skin is, the more reason there is to supplement with vitamin D. Being a black guy living in the northeast with a desk job, I go out of the way to supplement with vitamin D, but even still I'm only taking 1000 IU a day via a multivitamin which probably isn't even enough to ensure I'm not deficient.

After reading more about it, and reading this study, I think I am going to supplement with an additional 2000 IU of vitamin D to total 3000 IU.

[Mrpb]

Refer to my post, #3.

It's fairly individual as it is a fat-solubable vitamin, and it is primarily stored in adipose tissue. Also things like vitamin A-status matter.

Again, actual intake in IU does not mean anything per se, blood levels are what matter. If they are too high (> 50 ng/dl), you gradually increase your risk for soft tissue calcification etc (which increases your risk of heart disease for example).

Thanks. I haven't done a blood test yet. I know I probably should but can't be bothered at the moment.

I only supplement 400-600 i.e.. Going by your numbers that's very low.

I do eat 150 gram salmon 2-3 times a week.

[ZMan45]

Guru Performance has a podcast on vit D. Would link but on mobile.

[Mrpb]

Guru Performance has a podcast on vit D. Would link but on mobile.

http://itunes.apple.com/gb/podcast/w...885246231?mt=2

Many good episodes there.

[squall121]

I used to work at 50-54 celsius .. 2-4 hours daily exposed to the sunlight .I think I have excess vitamin D

[Mrpb]

I know the RDA isn't always the best recommendation, but 2,000-5,000 IU is quite the jump, and like you said would be very difficult to obtain through diet.

Just listened to that podcast. They also start supplementing roughly at 2,000 IU.

It's quite amazing how many of the athletes they tested were strongly deficient.

In my case 2,000 IU means 5 of the tablets that I bought, 10x the dutch RDA.