Vitamin D is an essential vitamin. But what value in the blood is considered optimal? Read the answer here.
Vitamin D has many functions in the body. However, its role in bone metabolism is particularly important. Vitamin D promotes the absorption of calcium and phosphate and is therefore essential for healthy bones. A vitamin D deficiency can therefore lead to bone deformities. But when should you help with food supplements and what vitamin D value is considered optimal?
How is the vitamin D value determined?
The vitamin D value is determined via blood values. According to the Robert Koch Institute (RKI), 25-hydroxyvitamin D, abbreviated as 25(OH)D, is evaluated for this. “Various reference values can be used to assess 25(OH)D serum levels,” writes the RKI. A commonly used classification is that of the US Institute of Medicine (IOM). There are classifications that indicate the serum value in nanomoles per liter (nmol/l), nanograms per milliliter (ng/ml) or micrograms per liter.
According to the RKI, the serum value fluctuates greatly. In winter in particular, the body in this country is usually unable to produce enough vitamin D itself. According to the institute, this does not mean that deficiency symptoms also occur.
Which vitamin D value is optimal?
According to the RKI, a vitamin D value between 30 and 50 nanograms per milliliter is optimal. Here is the overview:
25(OH)D in nmol/l
25 (OH)D in ng/ml
Vitamin D Deficiency
Bone disease in children and adolescents (rickets) Disorders of bone formation (osteomalacia) Porous bones (osteoporosis) 30 to <50 12 to <20 Suboptimal care 50 to <75 20 to <30 Lower normal range; adequate care as far as bone health is concerned 75 to <125 30 to <50
optimal vitamin D value
Possible oversupply, with potential health consequences
Cardiac arrhythmias Kidney stones Oversupply of calcium
What causes low vitamin D levels?
Vitamin D is the only vitamin that the body can produce itself. But for that he needs enough sunshine during the day. The Robert Koch Institute (RKI) writes that the daily requirement for vitamin D can only be met with a “stay outdoors”. In order for the body to be able to produce enough, it needs UV-B radiation in a specific wavelength – between 290 and 315 nanometers. Below the 35th parallel, this intensity depends on the season. According to the Swiss Federal Office of Public Health, light-skinned people in Germany have to spend up to 2.5 hours outdoors in the sun in winter so that the body can produce enough vitamin D. Darker skin types can hardly or not at all reach the necessary values in this country in winter. According to the RKI, low vitamin D levels in the blood can occur, especially in the dark season.
Although the body in this country can produce little vitamin D in winter, according to the RKI, it can fall back on reserves in fat and muscle tissue – provided you have spent enough time in the sun beforehand.
How long does it take for a vitamin D deficiency to clear up?
If low levels of vitamin D are found in the blood, the deficiency should be corrected. How long this takes depends on two factors: body weight and serum levels in the blood. The lower the vitamin D value and the higher the body weight, the longer it takes to correct the deficiency. 10,000 international units (IU) increase the vitamin D value by about 1 nanogram per milliliter.