by William Clearfield, D.O. for Longevinex

Welcome to Longevinex, where your health and wellness take center stage. As your dedicated health advocate, I am here to provide you with actionable insights to help you take charge of your well-being. Our focus on brain health has led us to develop a ten-step program that empowers you to preserve and enhance your cognitive functionality.

On September 22, 2023, (2) and October 2, 2023, (3), we delved into the first three steps towards preserving cognitive function. Today, we present step 4, Vitamin D. Let’s dive in and explore the secrets to a vibrant mind.

10 Steps to a Healthy Brain: (1)

  1. Keep Your Blood Sugar Balance
  2. Eat Healthy Fat
  3. Get Adequate and Restful Sleep
  4. Enough (but not too much) Vitamin D3 is Essential for the Brain to Function Properly.
  5. Get Your Gut in Order
  6. Maintain Adequate Methylation
  7. Balance Your Hormones
  8. 6 Fixes for A Healthy Heart
  9. Exercise
  10. Lifetime Learning

Knowledge of Vitamin D adequacy has evolved from merely the “Sunshine Vitamin” to playing numerous critical roles in our overall health and well-being. Research shows its importance, and despite the surprisingly widespread deficiency, ensuring we get enough Vitamin D is a crucial priority due to the benefits it provides and the risks it mitigates.

Produced on earth for more than 500 million years via sunlight exposure, a chemical in the skin called 7-dehydrocholesterol absorbs ultraviolet (UV) B radiation, converting to a pre-vitamin D3, which then transforms into vitamin D. (4)

Along with vitamins A, E, and K, Vitamin D is a fat-soluble vitamin. Unlike water-soluble vitamins such as Bs and C, which are absorbed in the bloodstream, fat-soluble vitamins dissolve in organic solvents but not water. As a result, they are stored in fat and can become toxic if ingested in excess. (5)

(For a little personal, historical background, back in my medical school dark ages, circa 1978, our instruction on Vitamin D, which lasted three minutes, was that it was a poison and never to be prescribed. The only use for Vitamin D was to prevent rickets soft bones, which “doesn’t happen in North America.” And that was the extent of our medical school training on Vitamin D.

In some circles, Vitamin D, despite a mountain of evidence to the contrary, continues to be disparaged. Click here for a “contemporary” alternative view.)

Top 9 Reasons to Maintain Adequate Vitamin D Levels:

  1. Bone and Muscle Health: Vitamin D is essential for calcium absorption in the intestines and maintaining adequate serum calcium and phosphate levels. Calcium and phosphorous are vital for normal bone mineralization and to control fracture rates in menopausal women and elderly men. Vitamin D deficiency leads to soft, thin, brittle bones. Vitamin D also supports muscle function and strength. (6-7)
  2. Immunity: Vitamin D protects the respiratory tract against infections like influenza, pneumonia, and bronchitis in all age groups.” (8-9) Vitamin D affects B, T, and antigen-presenting immune cells and is involved in cellular proliferation, differentiation, and communication within the immune system. Deficiency in Vitamin D increases the risk of autoimmune diseases and infection.” (10)
  3. Potential Cancer Prevention: Adequate vitamin D levels are associated with reduced risks of colorectal (11) and bladder cancer.” (12) There is no association between vitamin D levels and breast, lung, and several other less common cancers. (13-17)
  4. Heart Health: Early research connects Vitamin D deficiency to inflammatory conditions that increase cardiovascular disease risks, such as hypertension and elevated LDL (bad) cholesterol. Vitamin D suppresses renin, an enzyme that maintains sodium and potassium production, keys to stabilizing blood pressure.” (18)Vitamin D’s regulation of calcium metabolism, as noted above, affects the plasticity or hardening of the coronary arteries. Low Vitamin D levels increase the risk of cardiovascular disease, myocardial infarction, stroke, and early death.” (19)Total cholesterol, LDL (bad) cholesterol, and triglycerides negatively correlate with Vitamin D concentrations. (35)
  5. Blood Sugar Control: Vitamin D supports the insulin-secreting beta-cells of the pancreas, regulating insulin sensitivity and helping control blood sugar. Adequate Vitamin D levels are inversely related to the rates of type 1 and type 2 diabetes. (20) Vitamin D supplementation improves blood glucose levels and insulin resistance in diabetics.” (21)
  6. Brain Function: Vitamin D receptors and activating enzymes exist in immune cells and throughout the brain. Low vitamin D levels increase the risk of multiple sclerosis, cognitive decline, Parkinson’s Disease, dementia, and Alzheimer’s disease. (22-23)
    6A. Multiple Sclerosis patients have lower Vitamin D levels versus healthy controls. Vitamin D during a relapse is lower than in MS patients in remission. Low D is associated with higher recurrent relapse rates and MRI lesion activity.” (24) Living at higher latitudes with lower UV light exposure is associated with an increased incidence of multiple sclerosis. Springtime births are a risk factor, as wintertime gestation, lacking Vitamin D, contributes to MS risk. (25)
    6B. Parkinson’s Disease patients show similar Vitamin D patterns. Adequate Vitamin D reduces Parkinson’s severity and progression by stimulating dopamine synthesis and reducing neurotoxicity. (26) To complicate matters, genetic studies link vitamin D receptor abnormalities to Parkinson’s Disease risk and progression. (27)
    6C. Alzheimer’s Disease: Vitamin D reduces amyloid beta plaques, improves cognition, and promotes neuroprotection in Alzheimer’s patients. (28) As with Multiple Sclerosis and Parkinson’s patients, low Vitamin D levels increase dementia/Alzheimer’s risk. Vitamin D receptor genes are also associated with increased risk. (29)
    6D. Depression: Vitamin D reduces depressive symptoms by up to 20%. It synthesizes the neurotransmitters known for their roles in depression, dopamine, and norepinephrine. Vitamin D’s effect on cytokines and stimulating neurotropic and nerve growth factors improves the anti-depressive picture, seasonal affective (SAD), and other mood disorders. (30-33)
    6E. Cognitive and Executive Function: Vitamin D supplementation improves learning, memory, processing speed, concentration, the ability to start and complete projects efficiently or not, and the ability to multi-task easily, especially in winter climates where Vitamin D levels are low. (34)
  7. Anti-inflammatory Properties: Adequate Vitamin D is neuroprotective and promotes neural repair through its anti-inflammatory properties. Vitamin D inversely correlates with proinflammatory proteins, cytokines, IL-1β, TNF-α, IL-6, IL-8, IL-17A, IL-18, and IL-33.
  8. Anti-Oxidant Properties: Vitamin D has proven efficacy against asthma, joint pain, psoriasis, viral, bacterial, and fungal infections, and metabolic syndrome, a group of conditions including obesity, high blood pressure, high blood sugar, and abnormal cholesterol levels, dental cavities, weight control, macular degeneration, and even PMS. (36-44)
  9. Sleep: Vitamin D deficiency increases and is associated with sleep difficulties, shorter sleep duration, and nocturnal awakenings in children and adults. (45-48)

Dr. C’s Sleep Concoction” combines.

  1. Vitamin D 2000-5000 IU (See “How Much Vitamin D Do You Need” below)
  2. Melatonin 1-3 mg is a typical dose. (Rarely do we need more than 10 mg.)
  3. Magnesium taurate 400 mg-Start with one. If sleep remains inadequate, increase by one per week, up to four. Back off by one if you are too sleepy the next day.

Dr. C’s Sleep Concoction” is dosed two hours before bedtime. Though advertised as such, melatonin is not a “sleeping” pill. Melatonin stabilizes the circadian rhythm via the perception of light and darkness. (49) It takes approximately two hours post-ingestion to take effect. (50)

Recommended Dose for Optimal Levels:

Most laboratories consider 25 hydroxyvitamin levels of 30 to 100 ng/ml ‘normal.’ “Normal” in the world of laboratory studies, for the most part, is two standard deviations, 95.4% of whatever we are measuring. If we were to stop 1000 automobiles in a row on a busy street corner and measure their Vitamin D levels, 954 of them, 95.4%, would be between 30 and 100 ng/ml. (51)

Optimally, we want our Vitamin D to be in the mid to upper ⅔ range. The midpoint for Vitamin D is 65. (30+100/2= 65) To calculate an “optimal range,” we take one standard deviation, 68%, divide that by 2, 34%, and take that number above and below our midpoint. The optimal range for Vitamin D is 50-80 ng/ml. (52) In our clinic, we make this calculation for every lab test we perform.

Vitamin D3 is the form we recommend as it is the most productive and best absorbed of the Vitamin D supplements. It comes in 1000 IU increments. For every 1000 IU supplemented with a good quality supplement, we should see an increase in 25 hydroxy vitamin D levels of approximately 8 points in about 6-8 weeks.

Vitamin D3 comes in 1000, 2000, 5000, and 10,000 IU tablets and capsules. A 2000 IU dose will increase the blood level by 16 points (2 x 8). A Vitamin D level of 35, which is ‘normal’ but not ‘optimal,’ using a 2000 IU capsule would increase your level to 53 (2 x 8

=16 + 35 = 53). “Optimal,” but on the low end of optimal.

Two 2000 IU capsules would increase your Vitamin D level by 32 ng/ml to 67. 2 2000 IU caps= 4 x 8 = 32. Add the 32 to the baseline 35 in the above example, which equals 67ng/ml. With a midpoint of 65, 4000 IU supplementation is the correct dose.

Vitamin D also comes in a time-released twenty-five thousand units (equivalent to 3500 IU per day or 28 ng/ml increase in Vitamin D levels) and fifty thousand units (equivalent to 7000 IU or 56 ng/ml) once weekly doses. We use these extensively as they are convenient and inexpensive. Our biggest challenge is for our patients to remember to take them.

Take Vitamin D at bedtime. Vitamin D is not a sleeping pill but a sleep aid. (53) Vitamin D is a “pro” hormone. It improves the function of Growth Hormone (54) and Cortisol (55), our strength, energy, and stress hormones regenerated in the sleep cycle. Taking Vitamin D at bedtime aids each hormone’s metabolism.

Potential Side Effects and Contraindications:

Excess Vitamin D can result in hypercalcemia. Symptoms include nausea, vomiting, weakness, frequent urination, kidney stones, drowsiness, lethargy, and confusion. High calcium levels reduce neuronal membrane excitability in the brain and, on occasion, cause seizures.

With mild overdoses and serum levels between 100 and 140, the patient can be asymptomatic or complain of “unexplained” nausea, ringing in the ears, or vertigo. (56)

The remedy for Vitamin D overdose at these levels is discontinuing supplementation for approximately four weeks. You can recheck and recalculate your serum level or resume treatment at one-third to one-half of your previous dose.

Patients with hyperparathyroidism, namely overstimulation of the calcium-producing parathyroid gland, granuloma-forming disorders like sarcoidosis patients, those taking thiazide diuretics, digoxin, those with chronic kidney disease, or anyone with increased sensitivity to vitamin D need to be extra cautious with Vitamin D. (57)


Optimizing Vitamin D levels is crucial given the array of vital roles it serves in our bone, muscle, brain, mood, and immune metabolism. Adequate sunlight, food sources, and supplementation, when needed, help maintain recommended levels to unlock its many benefits.


Benefits of Vitamin D

Side Effects of Vitamin D


Stay tuned for Step 5 in our preserving and restoring brain health series: ”Getting Your Gut in Order.”


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