Why Vitamin D is the Rock Star of Vitamins

Well, it’s actually a hormone, and maybe that is why it does so many things. Optimal vitamin D along with a few others are at the hallmark of health, wellness and longevity in that the proper amount of vitamin D can help with mood, balancing of hormones, modulating immune function and autoimmune disease, keeping healthy blood sugar levels, and have positive effects on the cardiovascular system and brain function as well as reducing the risk of cancers. Yet it is estimated that most Americans do not have enough vitamin D for optimal health. Data extracted from the National Health and Nutrition Examination Survey (NHANES) study showed vitamin D insufficiency in more than 90% of the pigmented population and more than 75% of the white population in the United States. (1). In 2010, the Institute of Medicine tripled the recommended daily intake to 600 IU per day for those age 70 and under and 800 IU per day for those above the age of 70. However, many health experts believe that these recommendations may still be too low for optimal health and disease prevention.

Vitamin D deficiency was mainly associated with the bone deformity rickets in children and previously recommended dosing was based on the goal of preventing rickets. We now know that vitamin D has many, many functions in the body and vitamin D receptors can be found in most human cells, including the heart, brain, eye and reproductive system.

We also know that maintaining higher blood levels of vitamin D than previously recommended can help prevent illnesses such as cancers, heart disease, autoimmune disease, and many others. Low vitamin D also affects children and teens. In fact, a number of teen athletes may be low in vitamin D which can affect performance as well as cognition.

Vitamin D is essential for the absorption and utilization of minerals such as calcium and phosphorus. When vitamin D levels are low, the absorption of calcium is reduced and thus lowering blood calcium levels. In turn, the body starts a process of mobilizing calcium from the bones (melting your bones) to normalize blood calcium, a process regulated by the parathyroid hormone, and thereby increasing the risk for osteomalacia and bone fractures.

Less than optimal vitamin D levels have been associated with poor bone health, cardiovascular disease, cancer, autoimmune disease, and infection. (2)

Low vitamin D has also been linked to higher rates of metabolic syndrome (a group of risk factors, which together can dramatically increase the risk of heart disease, stroke, and diabetes), high blood pressure, diabetes, and heart attacks.

Suboptimal vitamin D levels in childhood and adolescence increase the risk of illnesses such as metabolic syndrome, hypertension, high blood pressure (3) and asthma later in life. (4) And some have presumed that precursors to cardiovascular diseases may originate in childhood.

Furthermore, vitamin D has been shown to affect mood, neurodegenerative diseases such as Alzheimers and Parkinson's disease as well as autoimmune diseases such as multiple sclerosis and rheumatoid arthritis.

Cardiometabolic

While much attention is placed on the benefits of vitamin D and bone health, most people are not aware of the metabolic and cardiovascular benefits of optimal vitamin D levels. Hypertensive patients exposed to UVB radiation showed a decrease in blood pressure (5) and lower levels of 25(OH)D levels were associated with higher risk of hypertension. (6)

Another study showed that low levels of 25(OH)D are associated with higher risk of myocardial infarction in men, (7) and low vitamin D levels are a predictor of fatal stroke. (8)

A higher vitamin D level was also associated with a lower risk of developing type 2 diabetes. (9) and individuals with both prediabetes and deficient 25(OH)D were significantly more insulin resistant and more likely to develop type 2 diabetes. (10) Low vitamin D levels were associated with cardiovascular disease among type 2 diabetics in another study.

Optimal vitamin D levels have been shown to reduce inflammation, and therefore suboptimal levels can exacerbate underlying inflammation. Subclinical inflammation has been linked to atherosclerosis and other chronic conditions.

Addressing the underlying cause of inflammation (chronic stress, nutrient deficiencies, poor diet) may be a better long-term approach to managing many chronic conditions.

Immune Function and Autoimmunity

Optimal vitamin D has been shown to improve immune function and reduce autoimmunity.

Lower vitamin D levels have been correlated with a higher incidence of upper respiratory tract infections, especially those with asthma and COPD (chronic obstructive pulmonary disease) (11)

In children, low vitamin D levels have been associated with influenza a in school-age children (12) and mild to moderate asthma. (13)

Also, Vitamin D may help with asthma control by blocking the inflammatory cascade as well as providing other anti-inflammatory effects such as increasing the production of interleukin-10, which has anti-inflammatory effects.

Lower vitamin D levels seen during winter months may be related to a higher incidence of viral respiratory infections. Vitamin D improves immune system function by modulating the activity of white blood cells and regulating inflammation. Vitamin D stimulates the release of antimicrobial proteins (responsible for destroying invading organisms) and suppresses inflammatory cytokine response (regulates inflammatory response), and this may explain how it helps with infections. (14)

Low levels of vitamin D are seen in people with multiple sclerosis and, in those suffering a single demyelinating attack associated with multiple sclerosis, vitamin D deficiency was correlated with developing the disease. Lower relapse rates are seen in those with higher vitamin D levels, and low levels of vitamin D are associated with higher levels of disability. (15)

Neurodegenerative Disease

Vitamin D acts as a neurosteroid, helps with gene expression and, reduces neuro excitation (which can lead to brain cell death in neurodegenerative conditions, and in types of head trauma) which can lead to cognitive decline. It also has neurotrophic (supporting the growth of brain neurons), neuroprotective and neuro immunomodulatory (modulates the immune response in the nervous system) effects.

Vitamin D deficiency in the elderly showed a higher prevalence of stroke and dementia and insufficiency was associated with more than twice the risk of all-cause dementia. (16)

Lower dietary intake of vitamin D has been associated with a higher risk of developing Alzheimer's, and higher intake of vitamin D was associated with a lower risk of Alzheimer's (17).

The proposed mechanism is thought to be vitamin D's ability to affect the clearance of beta-amyloid plaque, known to lead to Alzheimer's disease.

Low vitamin D levels have also been correlated with an increased prevalence of Parkinson’s Disease, another neurodegenerative disease (18).

Cancer

Vitamin D regulates cell growth and decreases proliferative activity and can also induce apoptosis (cell death). (20). Solar UVB radiation was associated with lower rates of 13 cancers, including breast, colon, ovary, and prostate. (19)

And, people with more sun exposure were less likely to die prematurely as a result of cancer. Researchers studying ovarian cancer have also found that higher Vitamin D levels correlated with a higher 5-year survival rate and a deficiency of Vitamin D to correlate with more aggressive cancer. Another study found that in post-menopausal women, both sun and diet high in Vitamin D may reduce the risk of breast cancer.

Hormonal Balance

Vitamin D in conjunction with progesterone can provide neuroprotection, thereby protecting brain cells during traumatic episodes. Vitamin D supports the natural function of many hormones, aiding in hormonal balance and optimal function, thus facilitating the beneficial effects of hormones. Low levels can cause estrogen deficiency in women, and optimal Vitamin D levels in men correlate to higher testosterone levels. Vitamin D may also play a role in neurotransmitter regulation and therefore affect mood and anxiety.

Why we don’t get enough vitamin D

Natural sunlight is our best source of vitamin D, but due to a variety of factors, most people do not get enough. Certain foods such as oily fish (salmon, mackerel, sardines), mushrooms exposed to UVB light. and fortified foods such as milk, orange juice, cereals, and breads do provide some vitamin D, but it’s usually not enough for optimal levels.

Natural sunlight is the best way to get vitamin D. Responsible sun exposure, about 5-10 minutes of exposure of the arms and legs about 2 to 3 times a week can be sufficient in many cases. Several factors such as sunscreen use, skin pigmentation, age, season, latitude and time of day affect the amount of vitamin D that is made from sun exposure and therefore, supplementation may be necessary to obtain optimal levels.

Healthy sun exposure can have significant health benefits and people who live in higher latitudes have increased risk of chronic diseases such as some cancers, multiple sclerosis, and hypertension. (20)

In fact, variations in blood pressure have been seen with changes in exposure to UVB light.

While the use of sunscreen may help with reducing the risk of skin cancers, it also blocks the formation of vitamin D. When applied correctly, sunscreen absorbs UVB radiation (thus preventing tanning) and reduces the production of vitamin D in the skin. In fact, sunscreen with an SPF of 15 reduces the capacity of the skin to produce vitamin D by greater than 98%. (21)

While there are several forms of UV light, UVB is essential for the formation of vitamin D. UVB radiation penetrates the epidermis and stimulates melanocytes to make vitamin D. Melanin, the pigment produced by melanocytes in the skin that give it color, acts as a natural sunscreen and blocks UV radiation thereby, inhibiting the production of vitamin D. Those with more pigmented skin require more time in the sun to produce vitamin D and explains why people with darker skin have lower vitamin D levels.

The amount of UVB light that reaches the skin is also dependent on the angle of sunlight and how much is filtered by the ozone which absorbs much of the UV light. The season (winter months), latitude (above 35 degrees), and time of day (early morning and late afternoon) affects this angle and may diminish the actual amount of UV light that is available. Apps such as d minder can be helpful to gauge the best time for your body to generate vitamin D.

The act of aging decreases the skin’s ability to make vitamin D from sunlight exposure in addition to the fact that the elderly may have mobility issues and therefore may not venture outside as much.

Lower levels of vitamin D are often seen in obese and overweight individuals because it is absorbed by adipose, leaving less available for use.

Vitamin D reacts with cholesterol in our skin when exposed to UV -B light from sunshine or tanning booths. This Vitamin D is converted in the liver to 25(OH) Vitamin D and then hydrolyzed in the kidney to the active form, 1-25 hydroxy D3 or calcitriol and that is what binds to the vitamin D receptor. So in order for vitamin D to work, we need exposure to enough of the right type of sunlight, the adequate function of the liver and kidney and for the vitamin D receptor to work appropriately.

Due to the above-mentioned factors, much of the population does not produce enough vitamin D to acquire optimal health benefits, and when necessary, supplementation of vitamin D should be considered to achieve optimal health and longevity.

What is optimal?

• The best way to check your vitamin D status is to have your Vitamin D level measured by a blood draw to ensure that it is in the optimal range. What do I mean by optimal? In order for your body to function at its best, is optimal. When looking at the basic guidelines for nutrients, the labeling directions are geared towards the lowest amount needed for the body to survive. What we are going for here is optimal living, not just basic survival.

• So, for your vitamin level to be optimal, you want it to be in the high normal range. Vitamin D levels can include 25-OH Vitamin D, and 1-25 OH Vitamin D. Optimal levels of 25 OH is associated with overall health.

• If your 25 OH Vitamin D is below 30 ng/ml, you are not optimal and, under the supervision of your health care provider, should consider taking a professional product containing Vitamin D3 to raise your levels. If your levels are between 30-50 ng/ml you are getting there and need to take Vitamin D to get closer to an optimal level of around 50-60 ng/ml.

Some important points to consider when choosing a Vitamin D supplement:

• Use the active form of vitamin D3 (cholecalciferol) to attain optimal levels.

• Choose a high-quality product that produces consistent results and is free from harmful contaminants, excipients, and fillers.

• Multivitamins don’t usually have enough vitamin D to raise your levels to be optimal. An average multivitamin may contain 400 IU which is 100% of the recommended daily allowance, but if you are going for your levels to be in the optimal range, oftentimes, that is nowhere near enough.

• Dosage will depend upon age, latitude, season, skin type, body weight, sun exposure, liver and kidney function, medication usage (such as anticonvulsants, steroids, and h2 blockers) and pre-existing 25(OH)D levels.

• Your current vitamin D status and the above factors will determine your Vitamin D dose, and your dose really depends on how deficient you are. You may need to take higher doses for several weeks and then back off dosing.

• An individual’s dose can vary from 1000 IU to 5000 IU per day or even more, so it is important to check with your health care provider and have your blood levels of 25(OH)D checked routinely to ensure levels are within optimal range and dosing is ideal.

• If your level is in the low range, you may need to take 5000 IU several times a week or more to get your numbers in the optimal range and then you can back off to about 1000 units a day or 5000 units a couple of times a week. Of course, this is a very general range, and everyone should have their levels measured to be successful.

• I recommend starting at 1000 IU to 5000 IU a day of vitamin D 3 (cholecalciferol) this is the active form. And keep in mind that you should always have your levels tested to make sure you are in the proper range.

• Take with a fatty meal or snack to improve absorption

• Take in the morning or early afternoon if possible

Things to watch out for:

• Vitamin D, along with Vitamins A, E, K and CoQ10 are fat soluble, so it will store in fat vs water soluble vitamins such as b where unused vitamins will be eliminated usually in your urine. So, it is important not to overdo it with the fat-soluble vitamins.

• Too high vitamin D may cause high calcium levels and result in calcification or undesirable calcium deposits in various organs

• Always have your vitamin D levels monitored by a functional medicine health care professional to ensure your levels are in the optimal range without becoming toxic.

The main take away here is that vitamin D has many functions in the body as there are vitamin D receptors all over the body. Several studies have demonstrated that higher vitamin D levels can be essential in preventing diseases such as metabolic syndrome, neurodegenerative diseases, cardiovascular conditions and much more. Responsible sunlight exposure is the best way to increase our body’s production of vitamin D, but many of us will require supplemental vitamin D in the active form of Vitamin D3 to have optimal levels. To be in the optimal range rather than the absolute minimum needed, most of us probably need to choose a high-quality supplement that provides enough vitamin D3 for blood levels of 25(OH) Vitamin D to be above 50.

Vitamin D is one of the most important hormones that predicts and imparts good health.

References

1. Adams, John S and Martin Hewison. “Update in vitamin D” Journal of clinical endocrinology and metabolism vol. 95,2 (2010): 471-8

2. Holick MF. Vitamin D deficiency. N Engl J Med. 2007;357:266–281.

3. Reis JP, von Mühlen D, Miller ER, Michos ED, Appel LJ. Vitamin D Status and Cardiometabolic Risk Factors in the US Adolescent Population. Pediatrics. 2009;124(3):e371-e379. doi:10.1542/peds.2009-0213.

4. Brehm JM, Schuemann B, Fuhlbrigge AL, et al. Serum vitamin D levels and severe asthma exacerbations in the Childhood Asthma Management Program study. J Allergy Clin Immunol. 2010 Jul;126(1):52-58.

5. Krause R, Buhring M, Hopfenmuller W, Holick MF, Sharma AM. Ultraviolet B and blood pressure. Lancet. 1998; 352: 709–710.

6. Forman JP, Giovannucci E, Holmes MD, et al. Plasma 25-hydroxyvitamin D levels and risk of incident hypertension. Hypertension. 2007;49(5):1063–1069.

7. Giovannucci E, Liu Y, Hollis BW, Rimm EB. A Prospective Study of 25-Hydroxy-Vitamin D and Risk of Myocardial Infarction in Men. Archives of internal medicine. 2008;168(11):1174-1180. doi:10.1001/archinte.168.11.1174.

8. 17 Jul 2008Stroke. 2008;39:2611–2613

9. Knekt P, Laaksonen M, Mattila C, et al. Serum vitamin D and subsequent occurrence of type 2 diabetes. Epidemiology. 2008;19(5):666–671.

10. Abbasi F, Blasey C, Feldman D, Caulfield MP, Hantash FM, Reaven GM. Low Circulating 25-Hydroxyvitamin D Concentrations Are Associated with Defects in Insulin Action and Insulin Secretion in Persons with Prediabetes. The Journal of Nutrition. 2015;145(4):714-719. doi:10.3945/jn.114.209171

11. Arch Intern Med. 2009 February 23; 169(4): 384–390. doi:10.1001/archinternmed.2008.560.

12. Urashima M, Segawa T, Okazaki M, Kurihara M, Wada Y, Ida H. Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren. Am J Clin Nutr. 2010 91:1255-60. Epub 2010 Mar 10.

13. Brehm JM, Schuemann B, Fuhlbrigge AL, et al. Serum Vitamin D Levels and Severe Asthma Exacerbations in the Childhood Asthma Management Program Study. The Journal of allergy and clinical immunology. 2010;126(1):52-58.e5. doi:10.1016/j.jaci.2010.03.043.

14. CANNELL JJ, VIETH R, UMHAU JC, et al. Epidemic influenza and vitamin D. Epidemiology and Infection. 2006;134(6):1129-1140. doi:10.1017/S0950268806007175.

15. Alharbi FM. Update in vitamin D and multiple sclerosis. Neurosciences. 2015;20(4):329-335. doi:10.17712/nsj.2015.4.20150357.

16. Michael F Holick; Sunlight and vitamin D for bone health and prevention of autoimmune diseases, cancers, and cardiovascular disease, The American Journal of Clinical Nutrition, Volume 80, Issue 6, 1 December 2004, Pages 1678S–1688S, https://doi.org/10.1093/ajcn/80.6.1678S

17. Cédric Annweiler, Yves Rolland, Anne M Schott, Hubert Blain, Bruno Vellas, François R. Herrmann, Olivier Beauchet; Higher Vitamin D Dietary Intake Is Associated With Lower Risk of Alzheimer’s Disease: A 7-Year Follow-up, The Journals of Gerontology: Series A, Volume 67, Issue 11, 1 November 2012, Pages 1205–1211, https://doi.org/10.1093/gerona/gls107

18. Knekt P, Kilkkinen A, Rissanen H, Marniemi J, Sääksjärvi K, Heliövaara M. Serum vitamin D and the risk of Parkinson disease. Arch Neurol. 2010;67(7):808-11.

19. Grant, W. B. (2002), An estimate of premature cancer mortality in the U.S. due to inadequate doses of solar ultraviolet‐B radiation. Cancer, 94: 1867-1875. doi:10.1002/cncr.10427

20. Buell JS, Dawson-Hughes B, Scott TM, et al. 25-Hydroxyvitamin D, dementia, and cerebrovascular pathology in elders receiving home services. Neurology. 2010;74(1):18-26. doi:10.1212/WNL.0b013e3181beecb7.

21. Michael F Holick; Vitamin D: importance in the prevention of cancers, type 1 diabetes, heart disease, and osteoporosis, The American Journal of Clinical Nutrition, Volume 79, Issue 3, 1 March 2004, Pages 362–371, https://doi.org/10.1093/ajcn/79.3.362