What’s the difference between vitamin D and vitamin D3
Medically reviewed by Sian Baker, Dip ION mBANT mCNHC
on February 20, 2021. To give you technically accurate, evidence-based information, content published on the Check My Body Health blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.
What is vitamin D?
Vitamin D is a fat-soluble vitamin that plays a number of important roles in the body. It is essential for the proper absorption of calcium and phosphorous, which are necessary for healthy bones and teeth. Vitamin D is also important for the immune system and may play a role in the prevention of certain diseases. It is found in a few foods, but it can also be synthesized by the body when the skin is exposed to sunlight.
What’s the difference between vitamin D and vitamin D3?
Vitamin D is the general term used to describe a group of fat-soluble secosteroids that are important for the absorption of calcium and phosphorous, and for the maintenance of healthy bones and teeth. Vitamin D3, also known as cholecalciferol, is one form of vitamin D. It is synthesised by the body when the skin is exposed to sunlight and is also found in some foods. Vitamin D3 is converted to its active form, calcitriol, in the body. Another form of vitamin D is vitamin D2, also known as ergocalciferol. Vitamin D2 is found in some foods and is also available as a dietary supplement. Both vitamin D2 and vitamin D3 can be converted to calcitriol in the body and are therefore considered to be biologically active forms of vitamin D.
Similarities between vitamin D2 and vitamin D3?
Vitamin D2 and vitamin D3 are both forms of vitamin D, which is a fat-soluble vitamin that plays an important role in maintaining bone health. Both forms can be converted to an active form called 1,25-dihydroxyvitamin D, which helps to regulate the body’s levels of calcium and phosphorus, and is essential for the formation and maintenance of strong bones.
The main similarity between vitamin D2 and D3 is that both forms can be converted to the active form of vitamin D and thus can perform the same functions. Both forms also can be obtained from food sources, including fatty fish, egg yolks, and fortified foods, and through exposure to sunlight.
The main difference between the two forms of vitamin D is the source. Vitamin D2 is found in some foods, including mushrooms and yeast, and can be synthesised by plants. Vitamin D3 is produced by the skin when it is exposed to sunlight and also obtained from animal-sourced foods such as fish, egg yolk, and liver.
Which form of vitamin D is better?
Both vitamin D2 and D3 are forms of vitamin D that can be converted to the active form and perform the same functions in the body. However, some studies have suggested that vitamin D3 may be more effective at raising and maintaining blood levels of vitamin D than vitamin D2.
One study published in the American Journal of Clinical Nutrition found that vitamin D3 was more effective than D2 at increasing blood levels of vitamin D (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3349454/). Another study found that vitamin D3 supplements were associated with a greater increase in 25-hydroxyvitamin D, the main form of vitamin D found in the blood, compared to D2 supplements.
Some researchers have pointed out that vitamin D2 has been considered as less potent as D3, however both forms of vitamin D are expected to have the same end effects in health. The most important thing is to have a proper dosage of it and maintain a healthy lifestyle, get enough sun exposure and consume a balanced diet.
It is important to note that, when it comes to getting the right amount of vitamin D, the best approach is to consult a healthcare professional and follow their recommended dosage, regardless of whether you choose D2 or D3.
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3. Vitamin D2 vs. D3: Which Should I Take for Bone Health?. Cleveland Clinic. Accessed February 15, 2021. (https://health.clevelandclinic.org/vitamin-d2-vs-d3-which-should-i-take-for-bone-health/)
4. Jetty V, Glueck CJ, Wang P, et al. Safety of 50,000-100,000 Units of Vitamin D3/Week in Vitamin D-Deficient, Hypercholesterolemic Patients with Reversible Statin Intolerance. N Am J Med Sci. 2016;8(3):156-162.
5. On call: Vitamin D2 or D3? Harvard Medical School. Accessed February 15, 2021. (https://www.health.harvard.edu/newsletter_article/vitamin-d2-or-d3)