Vitamin D3 in 50,000iu dosage is available from Amazon.com and Drugstore.com or from the manufacturers Ortho Molecular Products and BioTech Pharmacal on their websites. WebMD reports frequent sun exposure will result in sufficient vitamin D, but that people in Canada and the Northern United States are at risk for deficiency.
The sun is a very effective transmitter of vitamin D, with WebMD reporting that spending six days in the sun without sunscreen for 25 percent of the time it takes to become sunburned can create vitamin D sufficiency for 49 days without sunlight exposure. Because vitamin D is stored in fatty tissue and used as needed by the body, a large dose can sustain sufficiency over a long period of time.
Many people avoid the sun due to the risk of skin cancers or because they stay indoors, and others lack sufficient sun exposure due to climate. WebMD points out that older people and people with darker skin are less receptive to sun derived vitamin D. Because sun derived vitamin D is not always an option, supplemental vitamin D is available. Having a sufficient supply of vitamin D in the body prevents rickets and supports bone health, says WebMD. Vitamin D can also be used as a cancer preventative and to support heart health.