FERN-D is a brand name for a vitamin D3 supplement containing cholecalciferol, used to support various bodily functions including muscle, bone, and immune health.; It is a dietary supplement available in softgel form, often in bottles of 60 or 120 capsules, sold under the brand name FERN.; The supplement is marketed as a way to get vitamin D even without sufficient sun exposure.; Product detailsActive ingredient: Cholecalciferol (Vitamin D3)Form: Softgel capsulesBrand: FERNPurpose: Supports muscle, skeletal, and immune systems, and heart healthAvailability: Sold in various quantities, such as 60 or 120 capsules per bottle Usage and considerationsDaily use: The product is intended for daily use.; Supplementation: It is a good option for individuals who may not get enough vitamin D from sun exposure.; Timing: Some sources suggest that taking vitamin D close to bedtime might affect melatonin levels, so be mindful of timing.; Specific health conditions: Individuals with certain health issues, such as lymphoma, kidney disease, or sarcoidosis, should use vitamin D cautiously and monitor their calcium levels, as it may increase calcium levels in some case