Introduction to Vitamin D / To the top
Vitamin D is a hormone (secosteroid) because its structure is derived from the steroid precursor cholesterol like many of the other steroid hormones such as testosterone, estrogen, progesterone, etc.
85-90% of people are deficient to severely deficient in Vitamin D. This is because we get very little from our diets except for fish and in fortified dairy now. This is exacerbated by having jobs that are indoor. When we do go outside we use sunscreen which blocks UVB radiation that allows Vitamin D production to occur in our skin.
Other countries such as Russia take measures to obtain proper levels of Vitamin D. Unfortunately, this is an uphill battle in countries like the U.S. and Britain. (edit 2/2/10 — Finally getting some recognition.
This is particularly alarming because of the health benefits of Vitamin D on our bodies. Those with darker skin are often more deficient than others because it takes more sunlight to produce the same amount of Vitamin D as other ethnicities.
I would encourage everyone to start supplementing Vitamin D if they do not work an outdoor job, eat fish everyday, or drink at least a half gallon of milk a day or other dairy. There is 100 IU per cup at 16 cups in a gallon is 1600 IU total. Current government recommendation is 400 IU per day for adults and less for kids. This is too little to reach sufficient levels, especially for those allergic to dairy.
The benefits are too great to ignore.
Note: For those wondering, I did put a link to the one I buy in the conclusion. It’s the cheapest, high potency one I’ve found with good reviews.
Vitamin D: the panacea? / To the top
I hate to be one to claim that there is any “panacea” for modern societies ills, but Vitamin D deficiency sure fits a lot of the symptoms of many of the ills of our society (besides such things as processed food and overeating). Let’s examine what Vitamin D deficiency is implicated in.
1. Bone health
Of course, there is the obvious relation of Vitamin D and bone health and prevention of rickets (softening of the bones). Most compentent doctors will tell you to supplement with Vitamin D because it increases the rate of osteoblast activity leading to faster healing from bone breaks. In addition, like the study above indicates there is evidence in post-menopausal women (because lack of estrogen is correlated with osteoporosis) that it decreases the risk of fractures as well.
A bit more on fractures anecdotally from an MD plus some additional commentary on blood levels that may or may not be optimal in the comments.
Vitamin D is also implicated in many upper respiratory tract infections. For example, Vitamin D deficiency is implicated with Influenza (1) (2) and tuberculosis and other viral respiratory tract infections. Also, the recent swine influenza epidemic can also be countered with supplementation of Vitamin D. The largest study on Vitamin D to date showed that Vitamin D deficiency is related to an increased amount of the common cold and other upper respiratory tract infections (URTIs and RTIs).
The modulation of the immune system by Vitamin D produces anti-microbial peptides such as cathelicidin and defensins. Cathelicidin and other AMPs strongly protect against bacterial, viral, and fungal infections (1, 2, 3, 4). Vitamin D also increases and stimulates activity in monocytes, neutrophils, natural kill cells and other T lymphocytes. It increases IL-5 concentractions (a cytokine signaller) which also helps the immune system ward of bacterial and viral infections. This one article explains it a bit more in depth if you are interested.
Finally, a wiki has been produced on Vitamin D and influenza. It goes into a bit more depth than this article, so feel free to browse it if you want more proof.
My own experience with Vitamin D and influenza was that my fever was obliterated in one day, and I returned to full health within 3 days. Normally, going through a full course of the flu takes at least 5-7 days to heal from.
Vitamin D is also associated with decreased risk of at least 15 different types of cancers such as colorectal, breast, ovarian, pancreatic, etc. (1), (2), (3). The significant part of this is that supplemention or sun exposure for as little as 1,000-2,000 IU decreased risks of having a lot of the above cancers by as much as 40-77% or more.
The above immunomodulation contributes to this decreased cancer risk. Natural killer cells, for example, help prevent and destroy cancer cells.
We are told to avoid sunlight because of the damage to our skin and potential for developing skin cancer. This is partially true. There is an increase in two skin cancers from sunlight: basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). However, risk of melanoma decreases with increased exposure to sunlight. The key point here is that BCC and SCC are “benign” cancers in that they rarely metastasize. Melanoma easily metastasizes (aka becomes malignant and spreads) and subsequently makes up approximately 90-95% of all skin cancer deaths. Melanoma risk is increased substantially by sunburns, especially in younger populations.
Thus, it is important to increase sun exposure without sunscreen if at all possible while avoiding sunburns, or to supplement with Vitamin D or obtain the necessary amounts in your diet.
4. Cardiovascular disease
Vitamin D is found to decrease the risk of cardiovascular disease. For instance, another study indicates that there is an increased risk of hypertension, increased VLDL triglycerides, impaired insulin metabolism, and lipoprotein lipase activity with Vitamin D deficiency. Indeed, Vitamin D deficiency is associated with atherosclerosis (accumulating plagues), coronary artery disease, high cholesterol levels, and increased risk of myocardial infarction (heart attack) during the winter.
The theory on Vitamin D deficiency and increased risk of cardiovascular disease is because of cholesterol. Remember in the beginning when we examined that Vitamin D is produced through reactions involving cholesterol? Well, if you are Vitamin D deficient, your body is going to try to up your levels of cholesterol to try to synthesize more Vitamin D from the little amount of time we spend in the sun as modern humans.
Thus, cholesterol increases, LDL and vLDLs (bad lipoproteins) increase to carry the cholesterol to where it needs to go. HDLs decrease as cholesterol does not need to be removed from the skin and other tissues as the body needs it there to synthesize Vitamin D at an sun exposure. Inflammation abounds and leads to atherosclerosis, high blood pressure, and other cardiovascular maladies.
It’s really quite an interesting chain of events, but extremely good that decreasing risk is so easy. However, extremely sad that most doctors and people are unaware.
Vitamin D is linked with inhibiting proinflammatory cytokines and preventing low extracellular calcium levels which modulate endothelial inflammation. As you may well know, our diets in the modern age are pro-inflammatory because of the large amount of carbohydrates we eat. We also get very little omega 3s with disproportional increases in omega 6s (omega 3s are anti-inflammatory, omega 6 are pro-inflammatory). For example, meat and chicken such as grass fed vs. grain fed show improved omega 3 vs. omega 6 ratios for the former rather than the latter. A pro-inflammatory diet is associated with poor healing, and a lot of the illnesses above.
6. Intestinal / gut health
Likewise, with the point above about inflammation which is a major player in any of the inflammatory bowel diseases such as Celiac’s, irritable bowel syndrome, etc. (2) Part of the problem is that the inflammation in the gut prevents proper absorption of nutrients, one of which is Vitamin D. If Vitamin D levels are low as we already noted it cannot help much with down regulation of pro-inflammatory cytokines. Thus, malabsorption of Vitamin D and the ensuing increased inflammation leads to a progressively worse condition.
Note 1: Both inflammation and instestional gut health are actually sub-sets of immunomodulation (as is cardiovascular health and cancer risk to some extent). All of these are interconnected.
One meta-study review indicates that Vitamin D deficiency may be indicated in cancer, heart disease, multiple sclerosis, diabetes, autism, and a host of other illnesses.
There has been some debate about Vitamin D deficiency and autism. There may be a link as low Vitamin D levels in either the mother during pregnancy and/or the child during development. Further studies are obviously required.
8. Depression / Seasonal Depression / Schizophrenia
There is some indication that Vitamin D deficiency is also associated with depression and seasonal depression. (1), (2), (3), (4), (5). If you are prone to moody swings especially with the seasons, it may be a good idea to supplement with Vitamin D.
Vitamin D deficiency may also be linked up with schizophrenia (2) (3) because of abnormal brain development. This goes along with depression and autism as both of these are also potential neurological disorders.
9. Other autoimmune and chronic conditions
Vitamin D deficiency has been implicated in “multiple sclerosis, lupus, and psoriasis, and chronic conditions such as osteoporosis, osteoarthritis, metabolic syndrome, fibromyalgia and chronic fatigue syndrome.“ Additionally, besides the aforementioned fibromyalgia and CFS, there is some indication of improving outcomes of general musculoskeletal pain and myositis (3) (4).
Of note is this post from Whole Health Source. Great blog, highly recommended.
Vitamin D in particular plays an important role in immune responses (including inflammation), and also appears to influence body fat mass. Vitamin D status is associated with body fat and insulin sensitivity in humans (14, 15, 16). More convincingly, genetic differences in the vitamin D receptor gene are also associated with body fat mass (17, 18), and vitamin D intake predicts future fat gain (19).
11. Improvement of sleep quality
Unfortunately, there is nothing in pubmed at the moment about this that I’ve seen so far, but I feel it must be mentioned. A bunch of people have e-mailed me since the posting of this article and have mentioned that Vitamin D improves sleep quality. I have found this to the case as well. My sleep drastically improved (first time I was able to sleep through the night well in months) after starting to take Vitamin D.
If you sleep is crappy why not try it? Even though it’s just anecdotal evidence so far.
The reason why Vitamin D results in such a widespread effects in the body are for two reasons.
1. As previously mentioned, Vitamin D is derived from cholesterol and is “hormonal-like” in its effects on the body. Hormones are some of the strongest chemicals in the body and significantly alter cell growth, differentiation, metabolism and immune function.
2. Vitamin D receptors are ubiquitous within the body and appear on almost every type of tissue. This will be discussed later in section 4.
The fact that steroids are illegal regulated drugs within the USA and many other countries should tell you that they have powerful effects on the body. Vitamin D is similar in structure and exhibits similar effects. Thus, deficiency in Vitamin D causes widespread problems in the body.
Vitamin D deficiency is so widespread in the world’s population (especially American) and correlates well with the rapidly declining health of the populations. Though it is clearly not the only reason because of things like processed foods and overconsumption, it is one big reason to look towards this readily available simple and cheap solution to improving health and certain risk factors.
Of course, this does by no way mean that Vitamin D is a panacea that cures all ills. Rather, it should be used as one part of the plan to improve many areas of health simultaneously in accordance with healthy nutrition and exercise.
Note 2: There are many more studies than just the ones I listed here. I just chose a few to get you rolling with Pubmed. If you are interested in any of these topics, then search “vitamin D” with any of the bolded terms above and you will find a lot of studies on those topics.
Note 3: The prevalence of increased risk of cardiovascular disease and other such illnesses among those with darker skin color may by explained by Vitamin D deficiency because they are getting less from the sun than the rest of the fairer skinned ethnicities. Higher blood pressure, higher cholesterol, etc. result.
Vitamin D: athletic performance and levels / To the top
This is what most of us have come to this article for.
There is a large amount of evidence from studies implicating optimal Vitamin D levels and athletic performance. Fortunately, most of these studies which are from the old Soviet Union and Eastern Bloc countries (who knew something about increasing performance during the ’50s to the ’70s) are compiled into this PDF file.
There has also been some recent lay-person articles on the subject such as this one from T-nation.
Suffice to say according to the research it seems that approximately 50 ng/mL is optimal for athletic performance. Vitamin D does scale somewhat to weight so the heavier you are you may need to take a bit more or less depending.
The performance benefits are increased muscle mass, increased strength and explosiveness, and ability to recover. These results range from very significant to noticable. A lot of it depends on how deficient you were in the first place getting up to 50 ng/mL, and how Vitamin D responds through receptors in your muscles.
If you choose not to supplement, you must at least know how much Vitamin D production you are receiving from the sun and from other sources.
The maximum amount of Vitamin D produced from the sun is approximately 10,000 IU per day. This study also shows that it can be achieved by full body exposure for 20 minutes of UVB radiation (no sunscreen) in fair skinned individuals. If exposure is less than full body, it may take longer to achieve maximum levels. Similarly, another study indicates that darker skinned individuals may require 3-6x more time in the sunlight to achieve the same amount of Vitamin D production as fair skinned individuals.
Prolonged exposure to sunlight does not cause Vitamin D toxicity. Maximum production levels are approximately 10,000 IU per day because the precusors to Vitamin D3 reach an equilibrium. Further production is degraded within the skin. This correlates well with the proposed higher safety limit discussed in toxicity concerns.
If you are severely deficient from never going out in the sun and never drinking or eating dairy, it seems that supplementing 10,000 IU for about 4-5 weeks will bring up levels to around 50 ng/mL.
From there, maintenance of Vitamin D levels are about 100 IU for every 1 ng/mL. Thus, to maintain these levels, approximate supplementation of 5,000 IU/day is necessary.
I was severely deficient (rarely go outside, no dairy, rare fish) so I am doing the 10,000 IU/day for 4-8 weeks transitioning into 5,000 IU/day. I am currently starting week 5 at 10,000 IU/day at the time of the publishing of this article. I have had no ill effects so far.
Supplementation of Vitamin D should occur with magnesium and calcium as well as they work synergistically in the body. As long as you are eating a health amount of fruits, vegetables, and meat you should be fine; however, if you are worried you should take a calcium and magnesium supplement as well.
You want to be taking at least 100% of daily value of calcium and magnesium along with your vitamin D. This would be approximately 1000mg of calcium and 400mg of magnesium.
If you have not clicked on any of the articles before, please read this one on why 10,000 IU is recommending to bring up levels in healthy adults. This will also be further discussed in the next section.
Toxicity concerns have been raised with such high supplementation given the federal government’s current recommendation 400 IU for adults and less for children. Although there is talk about changing the proposed upper limit to 10,000 IU in healthy adults in a study that is supposed to be released in the spring. Another risk assessment confirms the 10,000 IU upper level safe limit in healthy adults.
If you are still worried, a safe bet with the above recommendations is 5,000 IU and close watch for toxicity symptoms. If your levels get too high, you may get feelings of intense thirst, having to urinate frequently, weakness, nervousness, potentially nausea and vomiting. If you encounter any of these symptoms you should back off supplementation as well as calcium rich foods.
There is a small percentage of people that are sensitive to doses so they may have to supplement with much lower amounts than the amount recommend above.
Knowing your levels
The only way to know your true levels are through blood tests. If you have biannual or annual visits to the doctor for blood work then you can request a 25-hydroxy Vitamin D test. The link above contains some guidelines to follow if you are to request one.
This article discusses the accuracy of some lab tests as well as other toxicity concerns of megadosing. It’s worth a read.
Alternatively, there are self tests you can use although I cannot vouch for the accuracy or veracity of such tests.
- 0-14.9 ng/mL = Severely deficient
- 15.0-31.9 ng/mL = Mildly deficient
- 32.0-100.0 ng/mL = Optimal
- >100.0 ng/mL = Toxicity possible
As stated, optimal levels for athletic performance should be at approximately 50 ng/mL. However, for normal health people who do not exercise it is generally best to aim for the 50-80 ng/mL range.
Vitamin D and post workout / To the top
As most of us know, post workout it is almost unanimous that you are supposed to take in only carbohydrates and protein to maximize protein synthesis.
However, there is this one study that always bothered me.
Milk ingestion stimulates net muscle protein synthesis following resistance exercise.
PURPOSE: Previous studies have examined the response of muscle protein to resistance exercise and nutrient ingestion. Net muscle protein synthesis results from the combination of resistance exercise and amino acid intake. No study has examined the response of muscle protein to ingestion of protein in the context of a food. This study was designed to determine the response of net muscle protein balance following resistance exercise to ingestion of nutrients as components of milk. METHOD: Three groups of volunteers ingested one of three milk drinks each: 237 g of fat-free milk (FM), 237 g of whole milk (WM), and 393 g of fat-free milk isocaloric with the WM (IM). Milk was ingested 1 h following a leg resistance exercise routine. Net muscle protein balance was determined by measuring amino acid balance across the leg. RESULTS: Arterial concentrations of representative amino acids increased in response to milk ingestion. Threonine balance and phenylalanine balance were both > 0 following milk ingestion. Net amino acid uptake for threonine was 2.8-fold greater (P < 0.05) for WM than for FM. Mean uptake of phenylalanine was 80 and 85% greater for WM and IM, respectively, than for FM, but not statistically different. Threonine uptake relative to ingested was significantly (P < 0.05) higher for WM (21 +/- 6%) than FM (11 +/- 5%), but not IM (12 +/- 3%). Mean phenylalanine uptake/ingested also was greatest for WM, but not significantly. CONCLUSIONS: Ingestion of milk following resistance exercise results in phenylalanine and threonine uptake, representative of net muscle protein synthesis. These results suggest that whole milk may have increased utilization of available amino acids for protein synthesis.
Why exactly is whole milk superior increasing amino acid uptake and rates of protein synthesis in this study even in isocaloric milk (significant in 1 category, more in 2, and slightly below in 1) plus totally dominating the FM?
This question bugged me for a while because the “butter fat” in milk doesn’t have any special qualities on its own. It sat at the back of my mind recently until I started researching more on Vitamin D.
As it turns out, Vitamin D is a fat soluble hormone that is best absorbed in the intestines with other fat. Fat is absorbed as micelles in the intestines to the lymphatic ducts. From there it is transported up the thoracic duct into the left subclavian vein.
Could it be that Vitamin D was acting on muscles post workout to boost protein synthesis OVER that of post workout carbohydrate and protein alone?
It turns out that muscles, along with most other tissues in the body have vitamin D receptors (VDRs). Most of which are located on the nuclear envelope and will modulate transcription of DNA.
It has been shown that VDR binding activates tyrosine kinase cascades in muscle cells. For you lay-people the activation of tyrosine kinase cascades are usually seen in cell growth and differentiation. Similarly, other studies (2), (3), (4), (5) have confirmed this finding and also shown involvement of VDR activity with calcium modulation and MAPK cascades in muscles (which are also responsible for cellular growth and differentiation). Ca2+ modulation by genomic and non-genomic mechanisms may account for potential increases in strength as Ca2+ binding is part of the process of myosin head binding to actin myofibrils before contraction.
In addition, research also demonstrates that Vitamin D regulation in involved with increasing the amount of insulin-like growth factor binding proteins (receptors) while IGF-1 can also elevate Vitamin D3 levels. Follow up studies (1) (2) have confirmed this and narrowed down the association of VDRs to the regions with IGF binding proteins 1, 3 and 5.
These processes and their anabolic effects on muscles are thoroughly discussed in Vitamin D, Volume 1 by Feldman, Glorieux, and Pike from pages 885-898 (google preview does not allow all the pages to be seen).
Again, for the lay-person you should know about growth hormone and its anabolic effects on the body, correct? The production of the IGF family (peptide hormones) is stimulated by growth hormone. They are responsible themselves for most of growth hormone’s anabolic effects on the body.
Increases in IGF binding proteins is similar in nature to insulin sensitivity. We often talk about insulin sensitivity and how insulin resistance causes type II diabetes. For example, increases in insulin sensitivity occur through exercise and regulation of carbohydrate intake. This means the amount of receptors are increasing, which means the body needs less insulin to deal with blood sugar levels. The opposite occurs in insulin resistance – receptors are down regulated and your tissues have less and less receptors until you get diabetes because your pancreas cannot produce anymore insulin.
In this case, increased amounts of IGF receptors leads to more sensitivity to IGF’s effects on the body. Thus, you will have more potent anabolic growth per amount of hormones produced in your body. We can all see why this may be potentially big for muscle gains. It is like taking steroids without taking steroids. In addition, there is the tyrosine kinase and MAPK cascades promoting muscular growth.
Unfortunately, there has been no studies done specifically on Vitamin D supplementation with and contrasted against carbohydrates and protein post workout. Although the whole milk vs. isocaloric skim milk does show indirectly that there is some benefit of probably Vitamin D absorption acting on increasing protein synthesis and growth within the muscle cells.
So what does this mean?
Honestly, I do not know what it means until there is an official study on it.
The milk in the study was only 237g which is approximately 1 cup. This is 25% of the recommended daily dose based on government nutrition standards. The current nutritional standard is 400 IU per day for 100%. Thus, the study participants were getting 100 IU. If they were deficient or severely deficient this may have made a big impact on their protein synthesis rates.
Now, compare this to supplementation with potentially 5,000 IU of Vitamin D post workout with carbohydrates, protein, and fat. There may be a HUGE effect on muscle protein synthesis.
My personal story: I started supplementing with Vitamin D at 10,000 IU for about a month. It just so happens that I usually workout then eat my dinner and take my supplements along with dinner. In this month I have been eating a bit less, but yet I have gained approximately 3-4 lbs of lean body mass and dropped a bit of fat. Now, the muscle gain could have occurred just from increased performance with my workouts, but I am almost positive that some of it has to do with increased protein synthesis post workout from the Vitamin D supplementation. Thus, I am continuing on with 10,000 IU post workout transitioning into 5,000 for maintenance.
If you are interested in maximizing your muscle gains, it may be a good idea to see if this can potentially work for you just like BCAAs/leucine have shown to have potent anabolic effects.
If you do try this, feel free to comment (1) whether it works or not. Also, post (2) whether you were deficient before or not, (3) when you started taking it PWO, (4) how many days/weeks it has been, and (5) your results compared to your normal PWO. I’d love to know if this works for you and get some data.
Note 5: This may also explain the “steroid-like” effects of the recommended gallon of milk a day (GOMAD) associated with such programs as Starting Strength and powerlifting. Vitamin D deficiency being corrected besides the calories and potential bovine growth hormones (although most of the peptide hormones should be hydrolyzed by enzymes in the stomach/intestines which is why I don’t think bovine GH plays a big role).
Conclusion / To the top
Most people are deficient or severely deficient of Vitamin D. If you are not working an outdoor job with significant sun or taking in significant amounts of dairy you SHOULD supplement. Those with darker skin are more at risk for Vitamin D deficiency.
1. There are significant health benefits to supplementing Vitamin D on borderline “panacea” levels if you are deficient which 85-90% of people are.
2. Getting a Vitamin D level of 50 ng/mL can increase your athletic performance.
3. Supplementing Vitamin D with fat post workout coupled with carbohydrates and protein may lead to increased muscle gains over just post workout carbohydrates and protein.
Vitamin D is fat soluble. Fat soluble hormones when taken “regularly” average out over 3-4 weeks. So if you wish to have say 5,000 IU/day and you only have 10,000 IU pills then one every other day is fine. Similarly, you could take 35,000 IU once every week. I have currently been taking 10,000 IU per day since this article was published until now (Oct 11 2009 – Oct 15th 2010) and feel great.
At 5,000 IU a day, Vitamin D supplementation is little more than $1 a month. And for the benefits above there is probably nothing that will benefit you more per cost ratio.
Recommended product / To the top
Vitamin D cost is fairly cheap. 360 pills at 10,000 IU for ~$24 is what I’ve bought and recommend. (“LOW052” coupon at checkout will get you $5 off plus save me some money on my purchases). With the discount it comes out to 1895 IU/cent.
Alternatively, someone notified me about this Vitamin D supplement. It’s a liquid if you don’t like soft gels albeit a bit more expensive than the above (1800 IU/cent)
Also, like I said earlier Vitamin D works synergistically with calcium and magnesium in the body. To get the full effect you need to have adequate amounts of each. If you’re eating adequate amounts of natural foods like fruits, vegetables, meats, etc. you should be fine and don’t need to supplement calcium or magnesium. Otherwise, supplement them. This cal-mag-zinc is the one I am using (MUCH cheaper than ZMA too). The alternative is to purchase them separately or go the ZMA route + Calcium on the side. Go whatever route you want.