by Dr. Laura Korman  

Q: Should I be taking Vitamin D? 

A: Most of us know that vitamin D is important for our health, but I am often asked about whether we need to take this as a supplement—especially while living here in sunny Florida—and if so, what dosage would I recommend? Both of these are important questions, but they are not necessarily straightforward ones to answer.  

First, we need to understand that a deficiency in vitamin D cannot be on the basis of a specific intake levels of this nutrient, but rather, adequate circulating blood levels of 25-hydroxy(OH)D, the active form of vitamin D3 we measure in a blood test.  

The reason is there are many variables such as our age, where we live, the color of our skin and the amount of sun exposure we receive, as well as certain health issues such as obesity, gastrointestinal disorders, and vitamin deficiencies like magnesium and vitamin K2. These variables determine the amount of vitamin D3 required to maintain blood levels of 25(OH)D in a healthy range. Therefore, I always recommend my patients have their blood levels of  25(OH)D tested before I answer their specific questions about dosing. 

The second factor to consider is there are significant—and quite confusing—differences in how lab values measure 25(OH)D levels in the “normal” range verses those levels shown to be in the  “optimal” range. About 42% of the population us estimated to be deficient in Vitamin D with levels of 25(OH)D less than 12ng/ml (deficiency according to WebMD). In addition, there is a slightly wider percentage of those with blood levels measuring less than 20ng/ml which is considered inadequate and requires supplementation.  

Moreover, as many as 80% of Americans could be at sub-optimal levels of 25(OH) D, meaning less than 40ng/ml. In fact some researchers now recommend levels of 60-80ng/ml for ideal health and disease protection.  

There has been a clear association with vitamin D deficiency and bone loss; however, evidence has emerged about this vitamin's role in almost all bodily systems including, most recently, our fight against bacterial and viral illnesses. In fact, one study released in late 2020, found that 82.2% of those with COVID-19 had vitamin D levels lower than 20ng/ml.  

The Health and Medicine Division of the National Academies of Sciences, Engineering and Medicine has reported an association between vitamin D and overall mortality risk from all causes of mortality including cancer. 

Having a serum vitamin D level of at least 40ng/ml has been shown to reduce cancer risk by 67%, compared to a level of only 20ng/ml. Levels of Vitamin D found to be the most protective are between 40 and 60ng/ml. Considering the fact that vitamin D is required for healthy genetic expression, and there are vitamin D receptors found throughout the body, cancer is not the only disease risk affected by vitamin D levels. 

Sufficient Vitamin D levels could lower your risk for Type 2 diabetes, high blood pressure, heart disease, and autoimmune disorders including multiple sclerosis, lupus, Hashimoto's and rheumatoid arthritis, as well as neurological conditions such as depression, dementia, Alzheimer's and epilepsy.  

Although vitamin D deficiency is diagnosed with a low blood level of 25(OH)D, few symptoms could suggest that you have sub-optimal levels. Nearly half of adults report having achy muscles, and researchers believe most of those afflicted are deficient in vitamin D.  

Bone pain can be a precursor to osteoporosis, and fatigue, common in many health conditions, were shown to improve after optimizing vitamin D levels. Hair loss, slow-healing wounds and dizziness were also associated with low levels of vitamin D. Multiple epidemiological studies have shown  vitamin D deficiency to increase the risk of recurring infections, particularly in the respiratory tract.  

So to answer the first question of whether someone should take a vitamin D3 supplement,  my answer in most cases would be, “Yes.” But to answer the second question as to what dosage, it’s probably safe to take somewhere between 4,000IU-5,000IU/day; however, for a long-term dose, you will need to have your 25(OH)D tested and fine-tune your levels to 60-80ng/ml for optimal health and disease prevention.  

I also need to mention there is a powerful synergistic benefit to taking magnesium and vitamin K2 in conjunction with vitamin D3. These will improve absorption of vitamin D3 in order to allow the proper distribution of calcium into bones and away from soft tissues including the arteries. I recommend a vitamin D3K2 supplement and a highly absorbable magnesium supplement as well. 

Hopefully, this provides a better understanding of how prevalent vitamin D deficiency is and how important maintaining not only “normal,” but optimal levels, are in reducing the impact of nearly all chronic illnesses and reoccurring infections. I also trust that you now understand how to test for your 25(OH)D levels and fine-tune your vitamin D3 dosing to optimize health and become more resilient against disease and illness. 

If you have any other questions or need help in the management of your vitamin D levels, please contact me at 941-629-6700.