In people whose 25(OH)D is 20 to 30 ng/mL (50 to 75 nmol/L), treatment with 600 to 800 international units (15 to 20 micrograms) of vitamin D3 by mouth daily is usually sufficient to maintain levels in the target range. The FDA developed DVs to help consumers compare the nutrient contents of foods and dietary supplements within the context of a total diet. The DV for vitamin D is 20 mcg (800 IU) for adults and children age 4 years and older [ ]. According to the Endocrine Society, vitamin D deficient adults should be treated with 50,000 IU (1250 ug) of vitamin D weekly [equal to 7143 IU (179 ug) daily] for eight weeks to achieve a blood level greater than 30 ng/mL (75 nmol/L). Maintenance therapy thereafter should be at least 1500-2000 IU (38-50 ug) per day. Główną postacią, pod którą witamina D występuje w krążeniu, jest 25-hydroksywitamina D (inaczej 25(OH)D, 25-hydroksycholekalcyferol, kalcydiol), czyli metabolit będący efektem pierwszej hydroksylacji cząsteczki witaminy D2 i D3 w pozycji 25, do której dochodzi w wątrobie. Based on this evidence, the committee concluded that the bone-strengthening benefits of vitamin D plateau when blood levels (as measured by a standard vitamin D blood test) reach 12 to 16 The consensus is that levels of 25(OH)D below 25nmol/L indicate 'deficiency'. Some have argued that this level is conservative. Raising the definition of "deficiency" or "sufficiency" to higher levels is inappropriate until results from randomised trials can show that maintaining such levels has clear health benefits and no health risks. The amount of 25-hydroxyvitamin D in your blood is a good indication of how much vitamin D your body has. The test can determine if your vitamin D levels are too high or too low. The Wskaźnikiem zaopatrzenia organizmu w witaminę D jest stężenie 25-hydroksywitaminy D w surowicy (25-OHD). W badaniu oznacza się nieaktywną biologicznie formę witaminy D, ponieważ poziom 1,25-(OH)2 D może być w normie nawet przy niedoborach witaminy w organizmie. Ile wynosi norma witaminy D3? Reference ranges for 1,25 (OH) 2 D may be reported as either pg/mL or pmol/L. The molecular weight of 1,25 (OH) 2 D is approximately 416.7, yielding the following conversion factors: 1 Vitamin D deficiency (serum 25-hydroxyvitamin D [25 (OH)D] < 50 nmol/L or 20 ng/ml) is associated with unfavorable skeletal outcomes, including fractures and bone loss. A 25 N186.