A question from a customer regarding the safety of 1,200 IUs of Vitamin D in Macula Complete prompted this post.
A study on vitamin D3 and multiple sclerosis resulted in data supporting the use of much higher doses of vitamin D3 for clinical research, and provided evidence that vitamin D3 intake beyond the current upper limit of 2,000 IU per day is safe by a large margin.
The current RDA is only 400 IUs per day. Based on a large number of new peer-reviewed studies suggesting that number to be too low, the RDA is expected to triple in the coming year.
The study, published in the September issue of the American Journal of Clinical Nutrition, included 12 patients in an active phase of multiple sclerosis (MS) who were given 1,200 milligrams elemental calcium per day along with progressively increasing doses of vitamin D3—from 700 (2,800 IUs) to 7,000 micrograms (28,000 IUs) per week—to determine the
"tolerability" of higher doses of vitamin D that may be required for therapeutic efficacy therapy. This study specifically assessed how well the body handles calcium levels relative to vitamin D concentrations in the blood.
At the beginning of the 28-week study, mean serum concentrations of 25(OH)D were 78 ± 35 nmol/L, rising to 386 ± 157 nmol/L (P < 0.001). Mean values of serum calcium concentrations and the urinary ratio of calcium to creatinine—both biomarkers of which high levels are associated with problems processing calcium in the body—did not increase or exceed reference values for any participant. Additional related biomarkers including liver enzymes, serum creatinine, electrolytes, and serum protein levels did not change. Disease progression and activity were not affected, but there was a mean decrease in the number of MS-related lesions per patient.
Participants' serum vitamin D concentrations reached twice the top of the normal range without resulting in hypercalcemia or hypercalciuria—detrimental conditions linked to problems with the body's processing of excess calcium.