Vitamin-D Selbsttest: which diet helps?

The question about which diet helps with a Vitamin D self-test is valid, but the provided context does not contain specific information on Vitamin D or diet recommendations. In general, Vitamin D is primarily synthesized in the skin through sunlight exposure. Dietary sources are limited: fatty fish (salmon, mackerel, herring), cod liver oil, egg yolks, and fortified foods (some dairy, margarine). There is no specific 'Vitamin D diet'; even an optimal diet often cannot correct a deficiency. The self-test measures 25(OH)D levels. If deficient, supplementation is recommended by guidelines (e.g., DGE, Endocrine Society) because dietary intake alone is usually insufficient. Evidence for a particular diet raising Vitamin D levels is weak – supplements are more reliable. Caveat: The test is not a medical diagnosis; consult a doctor for severe deficiency or symptoms. Evidence is 'mixed' because studies show diet alone has only a modest effect on serum levels.