Danny,

How much vitamin D3 to take and what constitutes a normal level of serum 25-Hydroxyvitamin D [25(OH)D] are contentious issues in the world of vitamin and mineral supplements. 

The Food and Nutrition Board (FNB) at the Institute of Medicine of The National Academies (formerly National Academy of Sciences) recommends an RDA of 600 I.U. vitamin D3/day and that a serum level of 25(OH)D, the active metabolite of vitamin D3, of ≥50 nmol/L (≥20 ng/mL) is generally considered adequate for bone and overall health in healthy individuals.

The Vitamin D Council suggests US Government's (FNB) recommended Adequate Intake for vitamin D is too low to receive many of vitamin D's benefits.  The problem they see with the current recommendations is that vitamin D influences a much wider array of physiological processes other than simply maintaining bone health and normal calcium metabolism.

They opine that for proper functioning, a healthy human body utilizes around 3,000-5,000 IU of vitamin D per day - indicating the current Government recommended intakes are not high enough to raise and/or maintain the vitamin D levels necessary for proper health.  They further suggest that 25(OH)D levels of 40 ng/mL to 80 ng/mL (100-200 nmol/L) is a safe normal range.

The American Board of Integrative Holistic Medicine claims most laboratories now consider a 25 hydroxy vitamin D level of < 30 ng/ml indicative of deficiency.  As physicians who treat patients with vitamin D3 and monitor their 25(OH)D levels offer that many of their vitamin D expert members consider a 25 hydroxy vitamin D [25(OH)D] level of 60-80 ng/ml (150-200 nmol/L) optimal; but this is expert opinion and not proven fact.

Finally, you've got other experts like Dr. Lewis, MD, an Integrative physician in Australia who treats vitamin D3 deficient patients on a routine basis, prescribing doses of vitamin D3 at 5,000 to 10,000 I.U./day and testing 25(OH)D levels looking for an optimum range of 40-80 ng/mL (100-200 nmol/L).

Given the above...  Who do you trust/believe?

It's no wonder that too many doctors are unfamiliar with adequate vitamin D3 dosing as recommended by the Vitamin D Council and expert physicians practicing in the field of Integrative and Holistic Medicine. 

It's also understandable that some physicians may be confused or caught in the cross-fire between the physician experts and the Food and Nutition Board.

It should be noted that the intake reference values for vitamin D and other nutrients are provided in the Dietary Reference Intakes (DRIs) developed by the Food and Nutrition Board at the Institute of Medicine of The National Academies.

DRI is the general term for a set of reference values used to plan and assess nutrient intakes of healthy people. These values, which vary by age and gender, include:

• Recommended Dietary Allowance (RDA): average daily level of intake sufficient to meet the nutrient requirements of nearly all (97%–98%) healthy people.

• Adequate Intake (AI): established when evidence is insufficient to develop an RDA and is set at a level assumed to ensure nutritional adequacy.

• Tolerable Upper Intake Level (UL): maximum daily intake unlikely to cause adverse health effects

The Vitamin D Council and several gold standard studies have determined that the skin of an average bathing suit clad human can produce the equivalent of 10,000 I.U. vitamin D3 in a matter of minutes exposure to direct sunlight and that supplemental dosing at a similar level would be essential to maintain normal levels.

As most of us don't get that kind of exposure to UVB, and most food types like milk fortified with vitamin D are insufficient, we're likely vitamin D3 deficient and need vitamin D3 supplements.

At issue is how much vitamin D3 to take as a normal maintenance dose and how much to take as a therapeutic dose to obtain symptomatic relief in the shortest time possible.

Again, who do you want to believe on this matter...  a group of four recognized experts in the field of nutrition and biochemistry who made up the Food and Nutrition Board (FNB) at the Institute of Medicine of The National Academies, (three of whom hail from tenured professor positions in academia and one from government) ... or the recommendations of the Vitamin D Council and the American Board of Integrative Holistic Medicine? 

Both of these organizations have memberships numbering in the thousands of practicing physicians who treat and test patients with vitamin D deficiencies on a routine basis.

Folks, I'm not a doctor so I suggest you see your primary care physician or neurologist and discuss the anti-inflammatory regimen along with contentious issue surrounding the RDA, AI and UL dosing with vitamin D3. Be sure to ask for the vitamin D3 test for 25(OH)D3.  This is a must particularly if you're dosing above 10,000 I.U./day.  Both the Vitamin D3 Council and the American Board of Integrative Holistic Medicine recommend this practice.  It's the only way you'll know your actual 25(OH)D3 levels and how they're being affected by your present level of dosing with vitamin D3.

Take care,

V/R, Batch