Vitamin D–Whats all the hype about?
Updated: Nov 10, 2018
Vitamin D. Everybody is talking about it. These days, we very rarely encounter a patient who does not either want their vitamin D levels checked or want to know much they should be taking. But honestly, do you know what the hype really is all about? Well, we are about to tell you. And you’ll be blown away by how detrimental to both our current and future health a deficiency in this vitamin can be.
Vitamin D is a fat-soluble vitamin that helps increase the absorption of calcium (important for your bones), magnesium (important for your heart and muscle function), and phosphorus (helps with formation of bones and teeth and allows the body to make protein for cellular growth). Vitamin D itself is more effectively absorbed when taken along with vitamin K. It is known as the “sunshine vitamin” because of the fact that sun exposure stimulates its production from cholesterol in the skin. But there is always a catch. Unfortunately, because of the use of sunscreens, expanding rates of obesity, and increasingly common gut and kidney problems, we as medical professionals are seeing more and more patients with deficiency and insufficiency. Interestingly enough, some of our most tan, sun-loving patients have the lowest vitamin D levels that we have ever seen!
The appropriate range for vitamin D really depends on the providers discretion and knowledge base. Our ranges go as such: < 30 is considered a deficiency, between 30-50 is considered insufficiency, and between 50-90 is considered an acceptable level. But, like we said before, this is based solely on the provider’s knowledge base and preference, along with considerations of a given patient’s co-morbidies.
Heres the science
Vitamin D deficiency has been linked with many different symptoms including, but not limited to, fatigue, hair loss, and joint pains. Some of the top co-morbidities include various cancers, gestational diabetes, cardiovascular disease and hypertension, migraines, and depression.
Multiple studies confirm that vitamin D deficiency is linked to certain types of cancers including colon and breast. These two have been the most heavily-studied cancers in regards to vitamin D deficiency. In a quantitative meta-analysis performed and published in the American Journal of Preventative Medicine in 2007, 5 studies were identified that showed an association between vitamin D deficiency and a high risk of colorectal cancer. They concluded that “A 50% lower risk of colorectal cancer was associated with a serum 25(OH)D level > or =33 ng/mL, compared to < or =12 ng/mL.” (1).
A very recent study published on July 5, 2018 in Nutrients looked at “observational studies, supplementation studies, and meta-analyses dealing with the effect of vitamin D on the occurrence of gestational diabetes, gestational hypertension and preeclampsia, preterm labour, bacterial vaginosis and caesarean section.” (2). The studies they reviewed had different recommendations when it came to levels of vitamin D and varied based on which condition they were reviewing. On review of this journal article, it seems that there needs to be more clinical studies which a larger amount of patient participation before optimal target levels of vitamin D can be determined.
As previously noted, low levels of vitamin D has been linked with many cardiovascular risk factors and increases in cardiovascular disease, insulin resistance, and metabolic syndrome (a combination of abdominal obesity, high cholesterol, elevated blood pressure, insulin resistance, and glucose intolerance creating a pro inflammatory state and pro-thrombotic state). A narrative review published in Clinical Hypertension in 2018, “summarized the evidence for the association of vitamin D, cardiovascular diseases and risk factors, including coronary artery diseases, stroke, and hypertension, and mortality, with special consideration to resistant hypertension.” (3). It is believed that with vitamin D deficiency reactive oxygen and G protein RhoA increases, which prevents glucose transportion ending with glucose resistance and metabolic syndrome. Basically, when vitamin D is low it causes stressors which can lead to cardiovascular and glucose issues. It was even shown in a study of over 6700 participants that patients with higher vitamin D levels had better cholesterol panels and a lower incidence of metabolic syndrome. “In 1978, a Danish study found that low vitamin D levels were significantly associated with angina and myocardial infarction.” (4) Yes, they were studying these correlations even back in the 1970s! It is also believed that low vitamin D levels are associated with hypertension by affecting something called the “renin-angiotensin system.” This is the same system that plays a role in glucose intolerance and metabolic syndrome. Yes, ALL OF THESE issues have been shown to be associated with low vitamin D levels. It doesn’t seem like such an unnecessary vitamin level to check now, right?
This month, a study was published by the Journal of Clinical Neurology questioning the association between low vitamin D levels and the frequency of migraine headaches (5). While still in the beginning stages of research.Vvitamin D might benefit chronic migraine sufferers and may be recommended at some point in the “supplemental regimen” that we offer our patients.
Major depressive disorder is very prominent in our society and seems to becoming even more prevalent as people are lifting up the curtain of stigma and actually talking about it. In a meta-analysis review of 4 randomized controlled trials, it was concluded that “vitamin D supplementation favorably impacted depression ratings in major depression with a moderate effect size. These findings must be considered tentative owing to the limited number of trials available and inherent methodological bias noted in few of them.” (6) This is another subject that needs more clinical data to support it, but it seems as though they are just scratching the surface of benefits that adequate levels of vitamin D could have on major depressive disorder.
Ways to raise your Vitamin D levels
The main sources of vitamin D are sunlight, oily fish, food products fortified with vitamin D, and over the counter (OTC) supplements.
People often believe that the primary source of Vitamin D is the sun. Remember, it is the “sunshine vitamin” after all! Sadly, this has become a myth and we are constantly re-educating our patients. There are numerous factors that affect the absorption of sun into the skin and negatively impact vitamin D production. These factors are “living mostly in an indoor environment, covering the skin with clothes, avoiding sunlight by staying in the shade and using sunscreen, sun exposure through glass, and air pollution with increased ozone concentration which absorbs ultraviolet light” (2).
In regards to the main food sources of vitamin D, the following foods contain the highest levels:
Fish oil (400–1000 IU/spoon of oil)
Wild caught salmon (600–1000 IU/100 g)
Eel (1200 IU/100 g)
Herring in oil (400–800 IU/100 g)
Sardines (300 IU/100 g)
Salmon in a tin can (300–600 IU/100 g)
Herring in a tin can (250 IU/100 g)
Tuna in a tin can (230 IU/100 g)
Shiitake mushrooms (100 IU/100 g)
Egg yolk (20–50 IU/1 egg yolk)
Cow milk (0.4–1.2 IU/100 mL)
Mothers milk (1.5–8 IU/100 mL)
Cheese (7–28 IU/100 g)
Surprised? Most of our patients are when they realize that dairy products really don’t contain much vitamin D (if any!), despite that we have been conditioned as a society to believe so.
Vitamin D supplementation can either be prescribed or OTC. Very high doses of vitamin D2 or D3 need a prescription. In our practice we tend to prescribe vitamin D2 50,000IU once a week for either 8 or 12 weeks (this depends on patient reliability) in capsule form. The liquid formulation is available as an 8000IU/ml dose. We only prescribe this dosage if levels are < 30 and use the vitamin D2 vs the D3 as it is believed it is easier on the kidneys. If the vitamin D level is between 30-50 we usually recommend vitamin D3 OTC 5000IU daily (depending on kidney function, risk for kidneys stones, and other co-morbidities). Multivitamins do contain vitamin D (up to 400IU), but if you have a legitimate deficiency it won’t be enough. Vitamin D3 OTC supplements come in various dosages ranging from 400IU up to 5000IU.
In the end…..
Vitamin D has quickly become not only a popular supplement, but a necessary one in preventative, integrative, functional, and conventional medicine. All areas of medicine acknowledge the importance of having optimal vitamin D levels along with the potential health benefits of supplementation. And there are likely many additional benefits that we don’t even know about. If you have never had your levels checked, make sure to ask your primary care provider to include them in your annual labs. If you have an issue with insurance coverage, the diagnosis of “fatigue” will usually provide coverage. But again, discuss this with your practitioner as there might be a more appropriate code to provide. Like we mentioned before, we try to ensure that our patients have a vitamin D level that falls in the 50-90 range. Discuss this range with your practitioner as co-morbidities need to be taken into consideration along with other possible interventions to promote adequate absorption.
Continue to Follow Your Gut,