Difference between vitamin D and vitamin D3
Vitamin D vs vitamin D3:
Increasing numbers of adults, and even children, are suffering from various types of bone abnormalities, autoimmune disorders and mood swings – all suspected to be caused by the same culprit – vitamin D deficiency. Seems our modern-day aversion to the sun, and a heated debate among the medical community, is having a devastating impact on our bones and our overall health. Vitamin D has Vitamin D3 connected to the name. Vitamin D and D3 are often confused and so, this article will help those who still confuse vitamin D and D3 to identify their differences.
What is vitamin D?
Vitamin D is a steroid vitamin, a group of fat-soluble prohormones, which encourages the absorption and metabolism of calcium and phosphorous. People who are exposed to normal quantities of sunlight do not need vitamin D supplements because sunlight promotes sufficient vitamin D synthesis in the skin. The best source of vitamin D is UV-B radiation from the sun. UV radiation levels vary depending on location, time of year, time of day, cloud coverage and the environment. For most people, adequate vitamin D levels are reached through regular daily activity and incidental exposure to the sun. During summer, the majority of people can maintain adequate vitamin D levels from a few minutes of exposure to sunlight on their face, arms and hands or the equivalent area of skin on either side of the peak UV periods (10am to 3pm) on most days of the week. Although vitamin D is commonly called a vitamin, it is not actually an essential dietary vitamin in the strict sense, as it can be synthesized in adequate amounts by all mammals from sunlight. An organic chemical compound (or related set of compounds) is only scientifically called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from their diet. Vitamin D is used for preventing and treating rickets, a disease that is caused by not having enough vitamin D. It is also used for treating weak bones (osteoporosis), bone pain (osteomalacia), bone loss in people with a condition called hyperparathyroidism, and an inherited disease (osteogenesis imperfecta) in which the bones are especially brittle and easily broken. It is also used for preventing falls and fractures in people at risk for osteoporosis, and preventing low calcium and bone loss (renal osteodystrophy) in people with kidney failure. Vitamin D is used for conditions of the heart and blood vessels, including high blood pressure and high cholesterol. It is also used for diabetes, obesity, muscle weakness, multiple sclerosis, rheumatoid arthritis, chronic obstructive pulmonary disease (COPD), asthma, bronchitis, premenstrual syndrome (PMS), and tooth and gum disease.
What is Vitamin D3?
Vitamin D3 is one of the most useful nutritional tools we have at our disposal for improving overall health. This vitamin is unique because cholecalciferol (Vitamin D3) is a vitamin derived from 7-dehyrocholesterol; however, Vitamin D3 acquires hormone-like actions when cholecalciferol (Vitamin D3) is converted to 1,25-dihydroxy Vitamin D3 (Calcitriol) by the liver and kidneys. As a hormone, Calcitriol controls phosphorus, calcium, and bone metabolism and neuromuscular function. Vitamin D3 is the only vitamin the body can manufacture from sunlight (UVB). Yet, with today’s indoor living and the extensive use of sunscreens due to concern about skin cancer, we are now a society with millions of individuals deficient in life-sustaining bone building and immune modulating 1,25-dihydroxy Vitamin D3. Vitamin D3 is both a vitamin and a hormone. It acts as a vitamin when it binds with calcium for proper absorption. Humans cannot digest calcium without adequate amounts of Vitamin D3. The most common reasons for Vitamin D3 deficiency in the United States relates to lack of exposure to sunlight and infrequent consumption of cold water fish such as wild salmon, mackerel & sardines. Vitamin D3 Deficiency is a condition in which the blood-levels of Vitamin D3 (usually tested for in the 25-hydroxyvitamin D3 form) are chronically low for an extended period of time. The condition is alarmingly common. People who live in cold, northern, mountainous regions, and those with darker-than-average skin are among the most at-risk groups, although anyone can become deficient if sufficient sunlight is not absorbed and if the individual is not obtaining enough of the nutrient through foods and supplements. The Recommended Daily Intake (RDI) of Vitamin D3 is set so low those mature individuals who consume this small amount (400 to 600 International Unites (I.U.’s)) are still likely to be deficient if they live north of the Tropic of Cancer or south of the Tropic of Capricorn.
What is the difference between Vitamin D3 and D?
“Vitamin D” is the general term for two types of molecules that function as Vitamin D in human physiology. The two types are Vitamin D3 (cholecalciferol) and Vitamin D2 (ergocalciferol).
There is some controversy within the scientific literature about the equivalency of these two forms of D. Most of the older research suggested that D2 may not be as effective as D3, but a recent study by Michael Hollick (a leading Vitamin D researcher) indicated that both forms function well in human physiology. Vitamin D3 is formed when ultraviolet light strikes the skin. The body turns into calcitriol, which is the active form of Vitamin D. Vitamin D3 is the vitamin that is used by humans. Vitamin D3 is naturally occurring whereas vitamin D2 is derived from plant. Hence the metabolic pathways are different and so does the use of metabolic products in the pathway. The only metabolic product of ergocalciferol which has some purpose in human body is Calcitriol. Other products do not serve any functions and need to be metabolized for elimination. Ergocalciferol is found only in tiny fractions even in plants. Vitamin D3 is a specific compound made in the body during a multistep process. Vitamin D3 is also the compound found in oral vitamin D supplements. Whether made internally or consumed as a supplement, vitamin D3 is converted easily to the active forms of D in the body.
Vitamin D3 needs smaller doses since the potency is higher. The dose needed to elicit a response is inversely related to the potency. Vitamin D3 can elicit the responses faster. Studies have indicated a dietary dosage of 4000 I.U is enough to meet the daily requirement for a normal adult. It means that the vitamin is effective in microgram quantities. The metabolic products of D3 are quite useful to the humans and find a specific function. D2 vitamin however enters the metabolic pathway to form products which are not useful to the human body. These products are found to be non-toxic.