What Is the Difference Between Vitamins D, D2, and D3?

What Is the Difference Between Vitamins D, D2, and D3? By W. Gifford-Jones MD and Diana Gifford How many times have we seen people in a pharmacy looking at the D vitamins. They’re standing on one foot and then the other and wondering which one to purchase. They are not alone. Let’s start with D. Vitamin D is very important for human health. One of its prime purposes is the absorption of calcium and phosphorus to keep bones healthy and strong. If we develop a deficiency in these two minerals as we age, our bones lose their strength year after year, and we develop a disease called osteoporosis, meaning week bones. This can result in bone fractures, and it may lead to spending time in a wheelchair. Vitamin D is called the “sunshine vitamin” because it’s the sun’s ultraviolet rays on the skin that trigger the production of vitamin D in the body. The best way to get D is to get out in the sunlight. Exposing your skin to the sun, without sunscreen, for 15 minutes a few times a week, to generate vitamin D is an effective way to maintain bones. You also get D from eating fish, egg yolks, meats and fortified cereals, and from drinking milk and orange juice. If you are on a vegan diet, it’s harder to get D from foods. Vegans need vitamin D supplements. The next question is, what is the difference between D2 and D3? They have different molecular structures. But here is the surprise. They are metabolized by your liver and kidneys into the same active form of vitamin D! So they also support good health through the absorption of calcium and phosphorus to increase bone and muscle strength. There are other benefits. These vitamins support the immune system to fight bacteria and viruses. Remember we have told you again and again that high doses of C increase immunity. Now we can add that D2 and D3 by becoming D also fight immunity. This is an important point as today an increasing number of people are developing diseases due to a lack of immunity. Vitamin D also helps to regulate blood sugar, support brain function, increase cardiovascular health, and lower the risk of certain cancers. The sun is so vital a source. Those who live in northern climates won’t get much D from the sun during the winter, even if standing out naked and freezing! The problem for indoor elderly people is compounded by aging skin and organs that don’t function as effectively. Does it matter which vitamin D supplement you purchase? It’s not one of the great decisions we have to make in life. There is some research that shows that D3 is more easily absorbed by the body and is therefore more effective. What’s more important is that you talk with your doctor about this vitamin, as some medications, such as steroids and statins, can involve interactions. In general, what is the recommended dosage? The first thing to remember is that vitamin D is fat soluble, unlike vitamin C which is water soluble. This means that vitamin D is stored in the body. This also means that it can build up in the body and lead to vitamin D toxicity, which can harm your health. For children 1 to 18 and for adults, the dosage is 600 IU (15 micrograms). If you are 70 or over, it increases to 800 IU (20 microgram). Many people are afraid of the sun due to the potential development of malignant melanomas. But researchers have also shown a relationship between skin cancers and low vitamin D levels. So over abstinence, moderation is the answer.er. Sign-up at www.docgiff.com to receive our weekly e-newsletter. For comments, contact-us@docgiff.com. Follow us Instagram @docgiff and @diana_gifford_jones