If you pay attention to the “official” recommendations for vitamin D intake issued by the Institute of Medicine (IOM), you might think that you can easily get all the vitamin D you need from moderate sun exposure and fortified milk or other foods. The problem is that the IOM’s Daily Recommended Intake (DRI) for vitamin D is a mere 600 IU per day, despite the fact that many experts now concur that much higher doses of vitamin D — often, upwards of 5,000 IU per day — are needed to ensure optimal health and longevity.
The IOM may mean well, but their logic for setting the DRI for vitamin D was seriously flawed. When they upped their recommendation from a pathetic 400 IU to 600 IU in 2010, they were looking only at research concerning vitamin D’s well-known role in supporting bone health. They ignored the volumes of research that have emerged in recent years showing that vitamin D is critical to overall longevity, cellular health, immune function and optimal cardiovascular health.
I firmly believe that if you live in the northern hemisphere and do not spend the majority of your time outdoors in the sun, you need to be taking a vitamin D3 supplement. In fact, I would say that if you were to only take one supplement, hands down it should be vitamin D.
But you do not want to take just any vitamin D supplement. If you take the wrong type, an insufficient dose or a supplement that is not formulated for maximum bio-availability, you could end up just wasting your money — and missing out on an opportunity to significantly improve your health. But more on that later.
First, let’s explore four reasons why vitamin D is so incredibly important, aside from its role is supporting our bones and skeletal system.
1. Vitamin D can help you live longer.
Simply put, taking vitamin D can help you defy death! Several studies have now alluded to vitamin D’s ability to reduce overall mortality, which simply means that individuals with higher blood levels of vitamin D tend to have a reduced risk of dying from any cause.
One such study evaluated data from 60,000 individuals and found a 29% reduced risk of all-cause mortality for those people with the highest blood levels of vitamin D vs. those with the lowest. Another older study from 2007 also demonstrated that individuals taking even moderate daily doses of vitamin D (400 IU-800 IU) had a 7% reduction in mortality from any cause compared to those not taking supplemental vitamin D.
These results, in my opinion, are staggering when you consider that something so safe and inexpensive can have such a profound effect on human longevity.
Vitamin D has shown impressive results when it comes to influencing cellular health. It plays an important role in promoting normal cellular growth and cellular longevity.
2. Vitamin D boosts immune function.
For many years, it has been speculated that vitamin D plays an important role in immune function. This hypothesis first came to light when researches noted that people living in more Northern latitudes suffered higher rates of certain autoimmune diseases. In 2006, researchers confirmed some of these suspicions when they discovered that people with the highest blood levels of vitamin D were 62% less likely to develop autoimmune problems than those with the lowest levels. Although these types of studies do not directly prove that vitamin D prevents these conditions, the correlations are strong and suggest a strong immune-modulating effect.
Another widespread theory regarding vitamin D and immune function originated from the observation that bacterial and viral infection activity and rates are much higher in winter months. Because blood levels of vitamin D fall significantly in winter months due to less sun exposure and weaker rays from the sun, it seemed logical that these factors might be correlated.
In 2006, a group of scientists researched this theory in more detail and found that the evidence in favor of a seasonal stimulus to increased infections was compelling. The online publication of the Harvard School of Public Health summarized the findings they cited to support their theory.
- Vitamin D levels are lowest in winter months.
- The active form of vitamin D alters the response of several immune cells, including damping certain damaging inflammatory responses and increasing the production of microbe-fighting proteins.
- Children with diagnosed vitamin D deficiency and the resulting condition rickets tend to have compromised immunity, while children who have more sun exposure tend to have stronger immune systems.
- Adults who have low vitamin D levels are more likely to report having had a recent cough or other signs of compromised immunity.
Other investigations into this issue have shown more of the same; higher blood levels of vitamin D support optimal immune health.