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May 2013

“Do I Need Vitamin D Supplements?” A Really Good Question

Vitamin D seems to be all the rage right now. And it’s probably for good reason: At least a couple decade’s worth of pasting ourselves with UV protective sunscreens and blocks have got us asking some pertinent follow-up questions:

“Am I blocking out something we vitally need from sun exposure?”

“Am I getting the daily amount of vitamin D I need?”

“Do I need vitamin D supplements?”

Vitamin D Supplementation (1)Chances are, if you’re not getting a good dosage of sun exposure on a broad section of your body each day, you’ve got good reason to ask ‘do I need vitamin D supplements.’ It’s estimated that at least a billion people worldwide are short of the recommended dosage of this vitamin – a nutrient that acts more like a hormone than a vitamin and is showing increasingly in studies to be vitally important for health.

If you’re an athlete or bodybuilder, it appears you’ve got even more reason to ask “do I need vitamin D supplements.” This stuff has been shown to have an effect on natural testosterone levels. By what mechanism this occurs is not really understood. But it appears that if you’re a male with low testosterone, a concurrent low blood level of vitamin D might be one of the reasons.

How about vitamin D’s importance for the nervous system? For years we thought it was vital only for good bone health – a tidbit of knowledge that might make us yawn and assume no worries about vitamin D levels until older age. It turns out, however, that we might need healthy levels for maximum brain function, a factor that could have an effect on how we score on any standardized test.

Possibly being smarter, stronger, and more virile. If those aren’t good reasons to ask “do I need vitamin D supplements”, I can’t imagine what would be.

‘Do I Need Vitamin D Supplements’… or Will Sunshine Do?

It’s estimated that an average beach lifeguard gets as much as 50,000 IU of vitamin D per day. Before assuming, however, that this is enough to cause an overdose (there is an upper safe limit), consider that sun exposure appears to be the body’s preferred method by which to obtain vitamin D.

But vitamin D doesn’t, of course, come directly from the sun’s rays; it’s a multi-step process. Upon contact with the skin, the UVB rays from the sun stimulate a type of cholesterol (called 7-dehydrocholesterol) that’s present in the skin. That stimulation by the UV turns 7-dehydrocholesterol into vitamin D3. The vitamin D3 then travels to the liver, via the bloodstream, where it’s converted into 25-hydroxycholecalciferol (25(OH) D, or calcidiol. This is actually a pro-hormone, which is the active form of vitamin D.

This whole mechanism by which the body makes UVB-stimulated vitamin D is fool-proofed with a built-in down regulator. In other words, even sun-soaked, Bay Watch-type beach lifeguards don’t have a chance of overdosing on their sun derived creation of the vitamin. The overdosing possibility is quite different with vitamin D supplementation, however, as we’ll discuss later.

Even though sun exposure can make vitamin D free and plentiful, it’s estimated that a huge portion of the population is vitamin D deficient. Many of us work in careers that keep us indoors and exposed to only intermittent sunlight that hits just our arms and faces. Considering that 30 minutes of full-body exposure to high-noon sunlight is required to produce 10,000 to 20,000 IU of vitamin D, it’s no wonder many of us are undersupplied.

Sources of vitamin D from food are woefully insufficient to compensate. Known foods with relatively high amounts of D3 are not exactly abundant. The top food sources comprise such disparate items as salmon, sun-dried mushrooms, and fortified milk.

Given vitamin D’s easily elusive acquisition, it’s not difficult to surmise that asking “do I need a vitamin D supplement” is a great question.

Vitamin D (1) 

'Vitamin D Sources': Getting enough vitamin D from the sun can be as elusive as sand-drawn text near the surf zone.

‘Do I Need Vitamin D Supplements’… for Higher Testosterone?

For guys who are experiencing low testosterone, there might be really good reason to ask “do I need vitamin D supplements.” At least one study shows a correlation between sufficient blood levels of vitamin D and raised levels of total testosterone. This should be of extreme interest to any guy who’s attempting to build muscle.

A 2005 study at the Ruhr University in Bochum, Germany demonstrated the correlation. Researchers took 54 healthy, overweight men who initially showed testosterone levels in the deficiency range and put them through a one-year randomized controlled trial. All the men had low initial vitamin D levels (below 19 ng/ml) and low initial testosterone levels (around 400 ng/dl). Thirty-one of the participants received 3,332 IU of vitamin D daily for a year while twenty-three of the subjects received a placebo. This gradually brought the vitamin D group’s blood levels of D up to above 50 ng/ml.

What were the results after a year?

The total testosterone of the vitamin D group was boosted by an average of 25% while the control group stayed, essentially, unchanged. And while this type of study does not prove cause and effect, the correlative difference between the two groups is significant enough to warrant further study.

It might also be worthy of eliciting a great question if you’re a bodybuilder, athlete, or just a middle-aged guy wanting to maximize testosterone: “Do I need vitamin D supplements?”

‘Do I Need Vitamin D Supplements’… for Better Cognitive Functioning?

In the past few years, quite a few articles in various publications have cited findings of connections between brain function and vitamin D. One of the more prominent pieces is titled ‘Does Vitamin D Improve Brain Function’, and was published in in Scientific American. It quotes Dr. Robert J. Przybelski, a research scientist at the University of Wisconsin School of Medicine and Public Health, in making the following connections between vitamin D and the nervous system:

  • There are receptors for vitamin D throughout the central nervous system and hippocampus.
  • Vitamin D activates and deactivates enzymes in the brain and cerebrospinal fluid that are involved in neurotransmitter synthesis and nerve growth.
  • Animal and laboratory studies suggest vitamin D protects neurons and reduces inflammation.

The article goes on in citing two European studies that show a link between cognitive function and vitamin D. The first study involved an assessment of 1,700 subjects, both men and women aged 65 and older. The second one looked at men in the age range of 40 to 79. In both studies, low vitamin D levels were correlated with impaired mental functioning. Outdoor Exercise (1)

Led by neuroscientist David Llewellyn of Cambridge University, the first study made an assessment of vitamin D levels and cognitive function by dividing subjects into four groups. These four groups were categorized by vitamin D blood levels and labeled as severely deficient, deficient, insufficient (borderline), and optimum. The researchers then had the subjects take a battery of mental exams in order to assess cognitive performance. The scientists definitely saw a correlation between vitamin D levels and results; low levels of D appeared to have a negative impact. In fact, those in the lowest quartile for blood levels of vitamin D were more than twice as likely to show cognitive impairment.

The second study, led by researchers at the University of Manchester in England, demonstrated a correlation between low vitamin D levels and mental ‘processing speed.’ Data from the research showed that the lower the blood levels of vitamin D, the slower were subjects able to process information. This was especially distinct among men over the age of 65.

Granted, these studies raise a lot more questions than they answer. Scientists don’t know if there’s a cause and effect between vitamin D levels and cognitive function. It’s also unclear whether optimum levels of vitamin D will reduce cognitive losses. But one thing is clear: If you want to be on the safe side of preserving your mental speed and acuity, it’s not unreasonable to ask…

… “Do I need vitamin D supplements?”

‘Do I Need Vitamin D Supplements”; are blood levels optimal?

You can’t really know what your vitamin D levels are unless you get a blood test. In other words, simply taking a haphazardly arrived-at daily dosage of vitamin D supplements could leave you with blood levels that are too high or too low. Complicating this a little more is the fact that the amount of sun exposure you’re currently getting can drastically change whether you even need supplementation.

So what’s the “right” amount of vitamin D?

There’s actually a fairly big window. The medical community generally considers anything from 30 ng/ml to 70 ng/ml as being the “normal” range. They consider 100 ng/ml to be “excessive.” But the toxic level isn’t reached until blood levels hit 150 ng/ml.

The Vitamin D Council recommends that adults aim for blood levels of 50 ng/ml.

So how much vitamin D supplementation would that require if sun exposure isn’t quite cutting it?

The answer to that is so dependent on age and the skin’s melanin levels that it can’t be estimated. Therefore, experimenting with vitamin D blood tests and supplementation (if needed) is the only way to find out.

“Do I Need Vitamin D Supplements?” It turned out that I did

Personally, I started by taking a vitamin D supplement, about 8,000 IU per day. Then, as an afterthought, I went in to get a blood test – about 5 days after starting this heavy supplementation.

What were my results out here in sunny Southern California?

My blood levels were 19 ng/ml. I was surprised, to put it mildly. I don’t even know what my blood levels had been five days prior, before starting to jack them up with that hefty supplemental dosage. I proceeded to increase my dosage to 10,000 IU per day, along with taking four Cod Liver Oil capsules (high in vitamin D) each morning.

After a full month of this, a second blood test showed my levels to be 46 ng/ml. That was a nice jump, but still short of the 50 to 60 ng/ml for which I personally wanted to aim. Based on the rate of increase I’d observed, I decided to continue the 10,000 IU for another week, then I’d cut down the dosage by at least half.

I’m now taking 4,000 IU per day along with the four Cod Liver Oil capsules. I’m awaiting the results of a vitamin D home blood test I administered well into my regimen of using this dosage. I will post the results of that test in the comment section below. This is simply for any value readers can get from my own experience; not as a recommendation for what anyone else should do.

In other words, if you’re asking “do I need vitamin D supplements”, get a blood test, consult your physician, and regularly monitor your levels from there.

But please, share your comments about vitamin D supplementation in the comment section below; other readers (and I) would love to hear your experiences, whether good or bad.