Many people take Vitamin D on a regular basis, and many more probably should, but don’t realize it. But what I find interesting is that few really know much about this important vitamin. So, let’s see how much YOU know!
1. Did you know that “Vitamin D” is a HORMONE with receptors in many body organ systems and Vitamin D targets over 200 genes in a wide variety of tissues, not just a “vitamin”? Having optimal Vitamin D stores significantly reduces all causes of death. Vitamin D is a secosteroid with an endocrine mechanism of action which is sequentially synthesized in humans in the skin, liver and kidneys. The bioactive hormone is1alpha,25-dihydrocholecalciferol [1,25(OH)2D3] or just D3 for short. Vitamin D2 is not naturally present in the human body. D2 and D3 are similar biochemically, but D3 is approximately 87% more potent in raising and maintaining serum calcidiol (the body’s main storage form of Vitamin D), and in producing 2-3x greater storage of Vitamin D than D2. So make sure your supplement is the bioactive form, D3.
2. Did you know that even people who live in sunny climates, like Arizona, Florida, and Texas, can be deficient in Vitamin D? In fact, while Vitamin D3 is made in the skin when 7-dehydrocholesterol reacts with sunlight, many things affect the degree to which this biosynthesis occurs, including time of day, seasons, location, smog/pollution, clothing, shade of skin (darker skin requires more sun), sunscreen use, depleting therapies and even high fiber diets and fiber supplements. Low-cholesterol diets and certain cholesterol therapies (statins and others) can decrease Vitamin D formation. Some estimates report that as many as 60% of people worldwide have Vitamin D deficiency or insufficiency.
3. Did you know adequate Vitamin D is needed for your body to absorb calcium? Many critical functions in the body—brain function, heart, nerve and muscle function, as well as bone health—are dependent on calcium.
4. Did you know that Vitamin D is fat-soluble and better absorbed for your body to use it when it is delivered in a capsule with OIL, rather than a tablet? And the type of oil is important. Long chain fatty acids such as olive oil facilitate the absorption of Vitamin D as well as healthy foods such as salmon, avocados, raw nuts and seeds, full fat dairy products and eggs.
5. Did you know Vitamin D deficiency is implicated in most of the diseases we face today? It has as many mechanisms of action as genes it targets. Look at all the body systems benefitted by optimal Vitamin D levels:
• Immune Function:Evidence suggests that Vitamin D plays a major role regulating the immune system, including immune responses to viral infection. Vitamin D deficiency leads to increased risk of influenza and respiratory tract infection (bacterial and viral) as well as increased risk of many cancers. Cell culture experiments support the thesis that Vitamin D has direct anti-viral effects. Another role is the potent immunomodulatory effects of the active form of Vitamin D in autoimmune diseases such as Rheumatoid Arthritis.
• Neurologic and Cognitive Health: Maternal Vitamin D deficiency may one of the risk factors for Infantile autism disease, likely by affecting fetal brain development. Many clinical studies over decades have shown Vitamin D supplementation is associated with the reduction of symptoms of depression and anxiety.
• Musculoskeletal Function: Vitamin D insufficiency/deficiency plays a significant role in sarcopenia, which is loss of skeletal muscle mass and strength due to degenerative changes in aging. Optimal Vitamin D improves muscle strength, muscle size and neuromuscular performance. Vitamin D deficiency in older people increases loss of muscle mass and increases risk of frequent falls and frailty.
• Healthy Blood Sugar Metabolism – Observational studies show that low Vitamin D levels are correlated with a higher risk of diabetes. Vitamin D supplementation reduces insulin resistance and improves glucose control.
• Cardiovascular Health – Vitamin D regulates blood pressure by acting on endothelial cells and smooth muscle cells. Vitamin D deficiency has been associated with cardiovascular disease risk factors and is linked to a higher incidence of cardiovascular disease and mortality.
• Healthy Cell Differentiation and Cancer Risk Reduction – Studies indicate that intake of Vitamin D in the range from 1,100 to 4,000 IU/d and a serum 25-hydroxyVitamin D concentration [25(OH)D] from 60-80 ng/ml is correlated with reduced cancer risk. There are many Vitamin D/cancer connections reported. In 2022-2023 alone, there were more than 900 articles on relationship between Vitamin D and cancer, including one study indicating that low circulating Vitamin D levels are associated with an increased risk of cancers. Supplementation of Vitamin D alone or in combination with other chemo/immunotherapeutic drugs may improve clinical outcomes even further.
• Bone Health – The body needs Vitamin D to absorb calcium, and the importance of Vitamin D in skeletal health and bone density is well established. Although many people think calcium intake is most important for bone health, insufficient Vitamin D reduces calcium absorption and has an enormous impact on bone density. Without adequate calcium absorption, the body has to take calcium from bone to maintain the normal calcium levels in the bloodstream, necessary for the function of all muscle (including the heart) and nerves, including brain. Leaching calcium from bone weakens existing bone and prevents the formation of strong, new bone. Clinical research shows that taking Vitamin D in oil in addition to separate calcium supplements, better supports healthy bone building and remodeling (turnover). Taking both adequate calcium and Vitamin D throughout life—as part of a well-balanced diet—may reduce the risk of osteoporosis.
• Dental Health – Vitamin D deficiency is associated with a wide variety of oral health disorders. Impaired Vitamin D synthesis can accelerate many of these conditions: defective tooth mineralization, resulting in dentin and enamel defects, increasing the risk of and progression of dental caries in children and higher prevalence of periodontitis and gingival inflammation in adults. Deficient Vitamin D levels are also linked to oral cancers and osteonecrosis of the jaw.
Natural Vitamin D levels found in humans living in a sun-rich environment (without supplementation) are between 50-70 ng per ml, but these levels are obtained by few modern humans. Supplementation of Vitamin D deficiency in otherwise healthy patients can range from 2,000-10,000 IU Vitamin D per day. The goal is to maintain year-round 25(OH) Vitamin D levels between above 60 ng/mL, with optimal being 70-90 ng/mL.
Unfortunately, there is a scarcity of Vitamin D rich foods. Unless you have adequate sun exposure and do not use sunscreen, you may be one of more than 60% of the public with Vitamin D deficiency.
How do you know if your Vitamin D stores are insufficient or deficient? The only way to is to have your blood level of Vitamin D stores checked regularly. The most reliable test is serum 25-hydroxy-Vitamin D-3. Optimal range for all the benefits of Vitamin D3 that I described above is 70-90 ng/mL
In those with serious illnesses associated with Vitamin D deficiency, such as cancer, heart disease, multiple sclerosis, diabetes, autism, immune dysfunction, and a host of other illnesses, supplement doses each day need to target maintaining blood levels in the 70-90 mg/ml range. People in this group may need more aggressive supplementation and more frequent monitoring of serum 25(OH) Vitamin D, as well as serum calcium and phosphorus.
When you consider supplementing Vitamin D, you may be wondering what other supplements should I take for bone health and Vitamin D absorption/function? I have recommended Vitamin D3 in olive oil capsules to my patients throughout my career. That is why I have included TruBioD3™ in my TruResilience™ Formula, which also includes TruZinc™. For those supplementing for optimal bone health, I would also recommend adding TruMagnesium™ and TruMultiV™ which contains additional minerals critical for healthy bone.
To your improving health!
Elizabeth Lee Vliet, MD
All Truth for Health Foundation Formulas are Meet or Exceed Quality Standards set by FDA Current Good Manufacturing Practices (cGMP). For more information, references from studies are listed in the Product Data Sheet.
Under medical practice regulations, we are unable to answer individual medical questions or make specific individual supplement recommendations for people who are not established patients of Dr. Vliet’s independent medical practice. *These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
