Most healthy adults need 600 or 800 IU of vitamin D per day. That means you can choose to take a multivitamin and mineral supplement that has this amount in it, you can take a combined vitamin D and calcium supplement, or you can take a dedicated vitamin D supplement.
Deciding what form of vitamin D to take
If you focus only on the bottles of vitamin D supplements at your local drug store, you may see several choices among that one vitamin. That’s because supplements are now available in many different forms and many different strengths.
The different forms of vitamin D are as follows:
Cholecalciferol is vitamin D3. This is the form that’s made in your skin by the sun or any ultraviolet B (UVB) rays.
Ergocalciferol is vitamin D2. This is the form also made in certain yeasts and mushrooms from the sun or UVB rays, but what’s in the supplement is chemically synthesized. It can be as effective as vitamin D3.
Calcidiol is the next step after the formation of vitamin D3. It’s 25-hydroxyvitamin D. This form isn’t available as an over-the-counter supplement.
Calcitriol is the active form of vitamin D3. This is a hormone and is regulated by the Food and Drug Administration and Health Canada as a drug. It’s very potent, so you wouldn’t want to take it anyway.
The form that you want to take is the one most like the form you make in your skin: vitamin D3, or cholecalciferol. The supplement is formed by extracting 7-dehydrocholesterol from the wool of sheep. The extract is extensively purified, dissolved in a liquid, and treated with ultraviolet light to make cholecalciferol. This vitamin D3 is further purified to make the supplement you take.
Choosing a multivitamin, mineral, or targeted supplement
Many people choose to take a multivitamin and mineral supplement because they get all or most of what they need for all of the required micronutrients in one pill. Only the minerals that are required in large amounts like calcium and phosphorus are provided in levels less than the current recommendations. (That would make the pill too large.)
You would want to avoid vitamin D in these formulations only if you want to take more vitamin D or if you want a targeted supplement. There are many good multivitamin and mineral supplements. Just read the label and make sure whatever you choose has at least 75 percent of the recommended levels of all the essential nutrients.
Taking more than one multivitamin per day to get higher doses of vitamin D may give you a toxic dose of another vitamin, particularly vitamin A.
Solid pill supplements are held together with binders. These binders are usually proprietary so you can’t tell exactly what they are. Some people find that certain binders upset their stomach. If you try a supplement with a binder that does that, try another brand.
Many women like to take a supplement that combines calcium and vitamin D to protect their bones. These supplements usually supply about half the daily requirement of calcium combined with half or more of the vitamin D requirement. Women are encouraged to take these smaller calcium doses with every meal to improve their absorption of the calcium. The table lists a few of these supplements.
|Vitamin D (IU)
|Cost and Size
|OsCal extra D
|Caltrate 600 soft chews
|Nature Made Calcium with Vitamin D