Given the vast benefits of vitamin D for cardiovascular and whole-body health, ensuring optimal vitamin D status is an essential part of every wellness program.
The best way to know your vitamin D status is to have your doctor measure the blood level of 25-hydroxyvitamin D (not to be confused with 1,25-dihydroxyvitamin D). The minimum level of 25-hydroxyvitamin D required for health is controversial, and can also vary by the method used for measurement.
However, most authorities have argued that a rock-bottom minimum 25-hydroxyvitamin D level of 30 ng/mL, or 75 nmol/L, is the point at which phenomena associated with deficiency begin to be corrected.
40 Noted vitamin D authority Dr. Reinhold Vieth of the University of Toronto has argued that a blood level of 40 ng/mL (100 nmol/L) should be achieved.7 Dr. Michael Holick of the University of Boston proposes that serum level of 25-hydroxyvitamin D is in the range of 30-50 ng/mL (75-125 nmol/L).
34 Another study showed that elderly men and women were at an increased risk of bone loss when their levels of 25-hydroxyvitamin D fell below 45 ng/mL (110 nmol/L), suggesting that maintaining 25-hydroxyvitamin D above 45 ng/mL may be crucial for all aging adults.
41 If vitamin D levels are low, consider supplementation to help reverse a vitamin D deficiency. Re-checking your vitamin D status after several months of supplementation is prudent to ensure that a deficiency has been averted.
New studies are showing that the dose required to achieve a healthy blood level of vitamin D is somewhere in the neighborhood of 1,000ï¿½??4,000 IU per day in the absence of sun exposure.42
Thatï¿½??s more than five times the Institute of Medicineï¿½??s recommended adequate intake, though still less than obtained through several minutes of midday sun exposure.
Vitamin D toxicity does not usually develop unless vitamin D intake exceeds 10,000 units per day or blood levels exceed 80 ng/mL (200 nmol/L).1,7 In fact, some scientists believe that the tolerable upper intake level of vitamin D intake should be revised from 2,000 IU/day to 10,000 IU/day.43