News about the health benefits of Vitamin D has met its peak over the last five years. Like Green Tea, it seems like every month when I review research articles, I read about the health benefits of Vitamin D. Many do not know that Vitamin D is not actually a vitamin, but is actually a fat-soluble hormone with wide-reaching effects on the body!
I attribute much of our epidemic of Vitamin D deficiency to our sedentary lifestyles lived largely indoors. Dietary sources of Vitamin D such as fatty fish are also consumed infrequently by most Americans and their acidic diets high in sugar, grains, dairy, and grain-fed animal fats. Darker skinned individuals are at greater risk for deficiency as more sunlight is needed to produce healthy levels of Vitamin D.
Much of the negative effects of our diet is that we do not balance it with liberal quantities of vegetables, especially of the green leafy variety which are also dietary sources of calcium!
Even more interesting is that Vitamin D supports much more than bone health and calcium metabolism. Vitamin D actually modulates on the genetic level (influences over 200 genes) and there are vitamin D receptors on every tissue in the human body!
Vitamin D Levels Normal Ranges
It is now well-known that significant percentage of Americans are deficient in Vitamin D. If you are from northern New Jersey, you may be aware of your need for Vitamin D. You may still even be at risk if you live in warm states like Florida or sunny states like Arizona!
Most laboratory ranges of Vitamin D tend to run as wide as 20-100 ng/mL although I'm seeing labs raise the bottom to 25-40 ng/ML. In terms of "wellness" and "functional" ranges of "healthy people", the lab ranges for Vitamin D should be between 40-80ng/mL with national wellness leaders like Dr. Mercola recommending 50-70 ng/mL.
Key Point: Many are deficient based on the wide ranges that laboratories tend to use. This means that many more may be deficient based on the healthy ranges of vitamin D!
Vitamin D helps to boost metabolic activity in many cells and in doing so, may actually promote cancer growth if levels are too high! In my practice, I do not like to see levels beyond 80 ng/mL, but I have yet to see a value that high in my career.
To have your vitamin D tested on your own, the test typically runs a cash fee of $80-125.
Vitamin D Dosing
Recommended daily allowances of Vitamin D are at 400IU. Recently the Institute of Medicine(IOM) posted guidelines that criticized excessive dosage of Vitamin D, but despite their criticisms, they still recommended a higher dosage of vitamin D at 600IU to support calcium and bone health, a 50% increase.
My personal criticism of that IOM report was that Vitamin D does much more than just support bone health and prevent Rickets. So it is in my opinion that most may actually need more than 600IU per day.
Many wellness-oriented practitioners tend to now recommend 1000-2000IU/day with doctors going as high as 5000-10,000IU/day when working clinically. Because there is risk of vitamin D overdose (and wellness concerns when your levels are too high), I recommend having your levels tested and having a trained professional recommend an appropriate vitamin D dosage for you.
Remember that excess Vitamin D can be stored in the liver for later use. Some doctors will megadose with Vitamin D to boost reserves over the short-term, but it is important to not try mega-dosing on your own.
Choose Vitamin D3 instead of Vitamin D2 (ergocalciferol) as it is more absorbable. Vitamin D is very inexpensive, even doages as high as 5000IU per day can cost only $6-$8/month.
Vitamin D and Immune Health
Vitamin D promotes a healthy immune system by promoting a healthy balance of your immune system. Vitamin D has been shown to be supportive for viral infections (1), allergies & asthma (2), and even patients with sepsis (3). Because Vitamin D has the capability of promoting different types of immunity, Vitamin D may be helpful for individuals living with autoimmune problems such as Hashimoto's Thyroiditis.
Vitamin D and Gut Health
The gut is the location of approximately 60% of your immune system. It is one of the primary defenses between the "outside world" and the "inside world". Vitamin D has been shown to support gastrointestinal integrity (4) is becoming a common recommendation for stomach and gut problems.
Vitamin D and Inflammation
Vitamin D is actually an anti-inflammatory hormone. It may be beneficial for patients with chronic pain and autoimmune joint conditions (5). This may be an indirect benefit of supporting immune balance and gut health.
Vitamin D and Weight Loss
Obese and overweight individuals are more likely to be deficient in Vitamin D (6). Whether supplementing with Vitamin D promotes weight loss or not is a question that may not be answered any time soon as there are too many competing factors. What is more likely the case is that people low in Vitamin D are probably more likely to live sedentary lives and consume unhealthy diets.
Key Tip: Just because you consider yourself "healthy" or skinny does not mean you cannot have low vitamin D levels
Vitamin D and Calcium Absorption
The links of Vitamin D levels and calcium levels are well-established. In my personal opinion, I think the large epidemic of calcium deficiency is largely a reflection of our epidemic of Vitamin D deficiency.
I will be more apt to substitue with Vitamin D alone without calcium. This is because calcium is highly regulated in the body and as your intake increases, your intestinal absorption decreases. When you are deficient, the body's intestinal absorption naturally increases. As long as you are doing weight-bearing exercise, eating a diet high in dark, leafy greens such as spinach and kale, and occasionally consuming calcium from other sources such as the soft bones in fish, I believe that you will receive enough calcium to support bone health.
I am not a huge proponent of dairy intake as it is a source of highly inflammatory fats, and adds an acidic stress to the body that the body balances by releasing calcium from bone! There is a lot of calcium in dairy products, but it is less available for absorption than other sources of calcium. Despite Americans high intake of dairy, calcium deficiency is still quite common.
Vitamin D and Mood
Many researchers blame Vitamin D for causing Seasonal Affective Disorder...a condition where individuals tend to become depressed over winter months. Once again this could be an indirect effect of gut health (which has large implications for mood and behavior), but the links are not entirely clear. The literature suggests that Vitamin D plays important roles in mood and cognition (7), but more research is needed to establish a more definitive link.
But we also know that Vitamin D has large influence on healthy gene expression which can yield affects in many body systems...
Vitamin D, Heart Health, and Metabolic Syndrome
Vitamin D has been shown to positively influence blood sugar balance and related complications from metabolic syndrome (8). Cardiovascular problems are often closely related to metabolic syndrome and account for many of the complications from insulin resistance and Diabetes.
Insulin resistance is also another primary contributor to mood swings and brain problems such as Alzheimer's or Parkinson's disease.
Vitamin D and Cancer
Immune cells helps to scavenge rogue cancer cells and act as your body's main defense against cancer cells. If you look at most foods associated with cancer prevention, many work by boosting immunity. Many advanced cancer treatments focus on artificially boosting levels of key immune cells. Vitamin D helps promote a natural balance of immune cells and hypothetically lets your body "choose" which cells it needs.
Vitamin D concentrations are correlated well with protection from Colon, Breast, and Prostate cancer (9)- three of the most common types of cancer.
Too much vitamin D may actually promote cancer growth, so make sure to stay within the healthy ranges of 40-80 ng/mL.