Energy status

25-OH vitamin D is the storage form of vitamin D that the body produces in the liver from vitamin D formed with sunlight or food. Vitamin D supports calcium absorption, ensures healthy bones and teeth, and plays an important role for muscles, nerves, and the immune system.

The 25-OH vitamin D test is the best method to check vitamin D status. Low levels can indicate too little sunlight, an unbalanced diet, or diseases and are associated with bone diseases such as osteoporosis or rickets. Excessive levels usually result from too high supplement doses and can strain the kidneys and liver.

Vitamin B12

Vitamin B12 is an essential vitamin required for the formation of red blood cells, the functioning of the nervous system, and the production of DNA. It is found almost exclusively in animal foods such as meat, fish, eggs, and dairy products.

A deficiency in Vitamin B12 can lead to anemia, fatigue, concentration problems, and nerve damage. Those at increased risk for a deficiency include primarily older people, vegetarians, vegans, or individuals with absorption disorders in the intestine.

Bilirubin, total

Bilirubin is produced during the breakdown of the red blood pigment hemoglobin and is further processed in the liver. It enters the intestine via the bile and is eventually excreted. The total bilirubin level in the blood indicates how well this breakdown and excretion process is functioning.

Slightly elevated levels can be harmless, such as in the case of Gilbert's syndrome. However, significantly elevated levels can indicate liver or bile duct diseases and often lead to a yellowing of the skin and eyes (jaundice).

C-reactive protein (CRP)

CRP (C-reactive protein) is a protein that the liver produces in response to inflammation. The level in the blood rises quickly when infections, tissue damage, or other inflammatory processes occur in the body. Therefore, CRP is often used as a general marker of inflammation.

A significantly elevated CRP level usually indicates an acute infection, while slightly elevated levels can also occur in chronic diseases. Normal values generally rule out a relevant inflammation.

Cystatin C

Cystatin C is a protein that is produced in all body cells and is filtered out of the blood by the kidneys. Since the production of Cystatin C in the body is relatively constant, the value is well-suited for assessing kidney function.

In contrast to creatinine, Cystatin C rises early when kidney performance declines. Therefore, it is considered a sensitive marker for timely detection of early kidney weakness.

Ferritin

Ferritin is a protein that stores iron in the body and releases it when needed. The ferritin level in the blood indicates how well the body's iron stores are filled and is therefore often used to assess iron status.

Low values usually indicate an iron deficiency or anemia. Elevated values may suggest inflammation, liver diseases, or iron overload.

Sodium

Sodium is an important mineral and electrolyte that regulates the body's water and salt balance. It also plays a central role in nerve signal transmission and muscle function. The body usually maintains sodium levels within a narrow range to keep essential functions stable.

Excessive levels (hypernatremia) often occur with fluid deficiency and can trigger thirst, confusion, or seizures. Low levels (hyponatremia) can result from significant fluid loss, kidney problems, or certain medications, leading to weakness, headaches, and, in extreme cases, consciousness disorders.

fT4 (free thyroxine)

fT4 is the precursor of the active hormone T3 and is predominantly produced by the thyroid gland. It circulates in the blood and can be converted into T3 in the organs to stimulate metabolism.

High fT4 levels typically indicate an overactive thyroid. Low levels, on the other hand, suggest an underactive thyroid.

TSH

TSH (Thyroid-stimulating hormone) is produced in the pituitary gland and controls the activity of the thyroid gland. It stimulates the thyroid to produce the hormones T3 and T4, which influence metabolism and many body functions.

High TSH levels usually indicate an underactive thyroid, as the body tries to boost hormone production. Low TSH levels, on the other hand, suggest an overactive thyroid.

fT3 (free triiodothyronine)

fT3 is the active form of the thyroid hormone that acts directly in the cells and regulates metabolism. It influences heart rate, energy consumption, digestion, and many other body functions. A large portion is produced by the conversion of the hormone T4 into T3 in the liver and kidneys.

Elevated fT3 levels usually indicate hyperthyroidism, while low levels may suggest hypothyroidism or a disturbance in the conversion of T4 to T3.