Vitamin D3 Deficiency? 25-OH vitamin D level
Vitamin D3, 25-OH Test
Vitamin D is important for the human body. It strengthens bones and has a positive effect on mood.
However, many people suffer from a vitamin D deficiency. They don’t eat enough foods containing this vitamin and don’t get enough exposure to sunlight. Vitamin D isn’t just something you take—it can also be produced in the body when exposed to sunlight. A vitamin D deficiency can weaken bones. It can also lead to a low mood.
This test measures the amount of vitamin D in the blood. Two different forms are present in the blood: the active form, 1,25-dihydroxy vitamin D, and the inactive form, 25-hydroxy vitamin D, which serves as a reserve for the active form.
Vitamin D is one of the few vitamins that our body can produce on its own. Under the influence of sunlight (ultraviolet radiation), vitamin D is formed in our skin and converted into its active form in the liver and kidneys. However, these amounts are not sufficient for everyone, nor under all circumstances. That is why we often need additional vitamin D from our diet. For example, fatty fish such as eel, herring, salmon, mackerel, and smoked herring are rich in vitamin D.
We need vitamin D for strong bones and teeth. It ensures that calcium and phosphate from our diet are absorbed and can be deposited in our bones and teeth as we grow. In addition, vitamin D is necessary to minimize bone loss (osteoporosis) as much as possible.
Some people get little or no exposure to daylight—for example, night shift workers, people with darker skin tones, or people who cover their skin completely. They are at risk of developing a vitamin D deficiency.
Decreased:
A low level of vitamin D in its inactive form (25-hydroxy vitamin D) indicates a vitamin D deficiency. This can be caused by insufficient sunlight, inadequate dietary intake, or poor absorption in the intestines. Low levels of vitamin D in its active form (1,25-dihydroxy vitamin D) can occur in cases of kidney disease. The use of certain medications for epilepsy can impair liver function, causing the liver to produce less vitamin D. A magnesium level that is too low can lead to a reduced calcium level. The body cannot correct this using vitamin D and parathyroid hormone (PTH). After administering magnesium and calcium, regulation is restored.
Vitamin D is produced in the skin, but sunlight must be of a certain intensity. If the body’s shadow is longer than its actual height, the body is no longer able to produce vitamin D on its own. In addition, vitamin D can be obtained from food (fatty fish, shiitake mushrooms, egg yolks, and cooking fats) or from vitamin D supplements. The plant-based form is vitamin D2, but it is converted in the body into the active metabolite just as effectively as vitamin D3 from animal sources. As a guideline for the relationship between vitamin D intake (cholecalciferol) and measured concentration, approximately 1 microgram per day can be used for every nmol/L increase. To increase 25(OH)D levels from 50 to 80 nmol/L, approximately 30 micrograms of cholecalciferol per day is needed for at least two months.
Below a serum 25(OH)D concentration of 20 nmol/l, the risk of rickets and osteomalacia is significantly increased (multiple publications).
- Muscle pain and symptoms occur at concentrations < 20 nmol/l (ref. Torrentes de la Jara), while muscle weakness and increased risk of falls occur at concentrations < 50 nmol/l (Janssen/Verhaar, Lips, Bischoff-Ferrari)
- Bone density decreases significantly at values < 50 nmol/l (e.g., Bischoff-Ferrari)
- By aiming for a minimum level of 75-80 nmol/l, gains can be made through risk reduction for multiple types of cancer and for autoimmune diseases (Dawson-Hughes, Biscchoff-Ferrari et al.)
- One must move to even higher values (> 100 nmol/l) for special results such as lowering the incidence of seizures in MS
- Up to a concentration of about 220 nmol/l, there is no danger of excessive calcium
Elevated:
A high level of vitamin D in its inactive form (25-hydroxy vitamin D) usually means that a person is getting too much vitamin D, for example, through vitamin pills or other supplements. High levels of vitamin D in its active form (1,25-dihydroxy vitamin D) can result from excessive production of parathyroid hormones or from conditions such as sarcoidosis or certain lymphomas.
High vitamin D levels (concentrations above 250 nmol/L) combined with elevated calcium levels can lead to calcification and damage to organs such as the kidneys. The body attempts to lower calcium levels by depositing calcium phosphate in the organs. This causes the organs to calcify and become damaged.
How do you address a vitamin D3 deficiency?
First, have a blood test to measure your vitamin D3 levels. If the level is below the minimum value of 80 nmol/l, it’s advisable to start taking a supplement. If the level is below 40 nmol/l, it is recommended to ask your primary care physician for cholecalciferol—a liquid form of vitamin D3—in a high dose, which is covered by health insurance.
It’s important to continue monitoring your D3 levels regularly to ensure they don’t get too high.
Also read our blog: https://info.bloodtesting.nl/jouw-vitamine-d-spiegel-hoog-genoeg/
