The Sunshine Vitamin in Just One Drop®Mom's Choice Awards Honoring Excellence600 IU Per DropA Factor in the Maintenance of Good HealthDietary Supplement100 DropsEuro Dropper™ TechnologyContents Certified NSF Vitamin D is made in the skin when exposed to summer sunshine (UVB) and is present in only a few foods. Vitamin D is necessary for healthy bones and normal muscle function. Vitamin D can be measured with a blood test for 25-Hydroxyvitamin D. The Institute of Medicine recommends this level should be higher than 20 ng/mL. A vitamin D supplement may be required to raise 25-Hydroxyvitamin D to healthy levels. Research findings show a 25 (OH) D blood level above 20 ng/mL is related to better health. A vitamin D3 supplement may be especially helpful for anyone who avoids exposing skin to sunshine.