As per the link we were watching it says even these levels are inadequate at the bottom of the scale as in order to have sufficient your level should exceed 80 nmol/L I believe. I also found out our GP can run the test for me and is going to next week. It's just a blood test. I will be interested in hubby's results as he started D3 in June of this year so with luck he is in an acceptable range without being toxic. Will keep you posted.I've actually decided boosting till he hits around 150 nmol/L but that is just my opinion
How is vitamin D deficiency determined?
The serum 25-OH vitamin D3 level is the best initial test for vitamin D deficiency. If there is a high level of clinical concern for vitamin D deficiency and a low-normal 25-OH vitamin D3 level is found, serum parathyroid hormone (PTH) concentration and a 24-hour urine calcium should be checked.
Although experts differ, the following definitions have been proposed (1):
Vitamin D sufficiency: 25-OH vitamin D3 is 20 to 80 ng/mL (50 to 200 nmol/L) and there is normal calcium homeostasis/bone metabolism.
Vitamin D insufficiency: 25-OH vitamin D3 is 4 to 20 ng/mL (10 to 50 nmol/L) with mild hyperparathyroidism, sub-optimal calcium absorption, and decreased bone density.
Vitamin D deficiency: 25-OH vitamin D3 is 0 to 4 ng/mL (0 to 10 nmol/L) with secondary hyperparathyroidism and malabsorption of calcium, causing osteomalacia.
Controversy over the lower limit of the optimal range of 25-OH vitamin D3 reflects awareness that the "normal range" varies depending on the reference lab. Most normal ranges are based on 95 percent confidence intervals for the general population. For example, in the United Kingdom, where there is relatively less light exposure (higher latitude) and less fortified food than in the United States, the reference range lower limit is 3 ng/mL (8 mM/L). In contrast, the lower limit in some laboratories in the United States is 18 ng/mL (45 mM/L) (2).
This variability has led to recommendations to abandon the lower limit of the normal range for serum 25-OH vitamin D3 and use a "target" concentration of 25-OH vitamin D3 instead, the latter derived from PTH measurements. This would be the 25-OH vitamin D3 concentration at which the mean serum PTH concentration starts to increase in population studies. This method would also eliminate geographical and seasonal variations that affect population-based normal ranges. With this "physiologic" approach, the optimal lower limit of 25-OH vitamin D3 has been found to be around 20 to 35 ng/mL (50 to 88 mM/L).
These recommendations take into account studies showing that some patients with 25-OH vitamin D3 levels in the low end of the "normal range" have clinical and pathologic evidence of vitamin D insufficiency, as indicated by an elevated PTH reflecting increased bone turnover and mild osteomalacia (3).
Although 1,25-(OH)2 vitamin D3 is the biologically active metabolite of vitamin D, it is not a good measure of vitamin D status. When patients are vitamin D deficient, the parathyroid hormone increases and drives the renal 1-alpha-hydroxylase, so that 1,25-(OH)2 vitamin D3 levels increase. It is only with severe vitamin D deficiency, when substrate is depleted, that a deficiency of 1,25-(OH)2 vitamin D3 occurs. Therefore, earlier stages of vitamin D deficiency can be missed by measurement of the level of 1,25-(OH)2 vitamin D3.
* Some experts feel that elderly people and veiled women living in northern latitudes need closer to 1,000 IU per day (5).
Vitamin D 1,000 IU
Stimulates absorption of calcuim, important for bone maintenance and plays a role in regulating blood pressure. Jamieson uses only vitamin D3. This is the nutrition industry's premium grade natural vitamin D source.