It is no news that low levels of vitamin D are associated with a variety of diseases, including osteoporosis and fractures, diabetes, cancer, cardiovascular disease including heart attacks and strokes, depression, asthma, inflammatory bowel diseases, autoimmune diseases such as multiple sclerosis, and even an increased risk of dying. I check vitamin D levels on all of my patients and consider it almost a “vital sign”, but many insurance companies do not reimburse vitamin D testing unless you suffer from osteoporosis. Go figure.
Vitamin D is like a hormone, affecting over 200 genes and thus almost everything in our body from head to toe, including our immune system. Vitamin D seems to make our immune system work better and be more capable of fighting infections, including viruses.
Vitamin D leads to a production of an antimicrobial peptide called cathelicidin, which has both antibacterial and antiviral properties. Maintaining an optimal vitamin D level seems to make us more resilient against flu and colds. In one study, a vitamin D level of 38 ng/ml (reached through taking a vitamin D supplement) cut common colds by half.
During 2020, we learned that those suffering from severe COVID are often deficient in vitamin D. Low vitamin D levels may be a predisposition for the infamous cytokine storm, an “unchecked” immune response to the COVID virus, causing severe lung damage and other life-threatening consequences.
A recent study of patients over 60 years of age who required hospitalization in the intensive care unit and ventilation due to severe COVID revealed that 94.2 percent of them had a vitamin D level less than 30 ng/ml, and almost 66 percent had a vitamin D level below 20 ng/ml.
While 20 to 100 ng/ml is considered a normal vitamin D level, a more optimal level seems to be around 40 ng/ml, according to most experts, and most functional medicine physicians would consider anything less than 30ng/ml inadequate.
The sweet spot likely depends on many individual factors, including genetics (such as genes coding for vitamin D production or vitamin D receptor). There might even be a difference between generating adequate vitamin D naturally – from the cholesterol in your skin through the action of sunshine versus getting it from a supplement.
Vitamin D is necessary for proper development of lungs and airways when we are in our mother’s womb. In fact, our increasingly indoor led lifestyle and thus low vitamin D level in pregnant women may be at least partially responsible for the higher rates of asthma in children. Indeed, vitamin D is now used in the treatment of asthma, but being proactive and preventative would be better than having to treat conditions we allowed to develop.
Evidence seems to be mounting that optimal levels of vitamin D may lower the risk of developing or dying from cancer, especially breast cancer and colon cancer.
We need exposure to UV light from sunshine for the production of vitamin D in our skin. The more pigment we have in our skin, the longer sun exposure we need to generate adequate levels. Skin pigment acts as a natural sunscreen, which can explain the much lower vitamin D levels in African Americans as well as their higher rates of severe COVID.
Although sunscreen may help to lower the risk of skin cancer and sun damage in general, it also blocks the formation of vitamin D in our skin. Living in a warm climate does not guarantee a perfect vitamin D level. Many medications accelerate the metabolism of vitamin D, and its levels also tend to be lowered by obesity. You would not want to overdose on vitamin D either, and take it along with vitamin K2 to prevent deposits of calcium in your arteries, but low levels are far more common than high levels.
Ask your physician to check your vitamin D level each year, ideally in the winter, when we tend to be exposed to less sunshine. And please, do not let insurance dictate whether or not you get a vitamin D test. Remember, your life is worth more than the $40 to $120 cost for the test.
