Age-related risk groups:
(1) infants
(2) elderly
Environmental risk groups:
(1) very limited exposure to sunlight or a source emitting sunlight equivalent light
(2) people at a high latitude (near North or South Poles) during winter
(3) submariners and astronauts
Dietary:
(1) no or limited intake of vitamin D fortified dairy products
(2) no or limited dietary supplementation with vitamin D
(3) no or limited intake in foods rich in vitamin D (fortified cereals, cod liver oil, eggs, fatty fish)
Other:
(1) dark-colored skin
(2) malabsorption
(3) pregnancy and lactation
(4) drug interactions reducing vitamin D utilization or increasing loss (anticonvulsants, antituberculous drugs)
(5) alcoholic
(6) renal failure
