Vitamin D3 is the common name for cholecalciferol. Vitamin D3 can be taken as a supplement to improve overall health or used to treat osteoporosis. It can also be used to treat conditions in which vitamin D3 levels may be low, such as in people who have underactive parathyroid glands, low levels of phosphate in the blood, or hereditary conditions in which the body doesn't respond to the parathyroid hormone. Vitamin D3 also encourages the kidneys to recycle phosphate back into the blood, which helps the blood stay at the right pH. Vitamin D3 is available for purchase over-the-counter (OTC).
Vitamin D3 Deficiency
Historically, vitamin D3 loss has been associated with rickets, a disease caused by low levels of vitamin D3 that commonly affects children. Children with rickets and adults who had rickets as children often have legs that are bow-shaped. However, while adults who are deficient in vitamin D3 do not typically develop rickets disease, their bones may start to become softer — a condition known as osteomalacia. People with digestive problems like celiac disease, liver problems, or Crohn's disease are more likely to have low levels vitamin D3. Sunlight is a natural source of vitamin D3, and people who rarely or never go outside (for example, those in nursing homes or bedridden hospital patients) are most likely to be deficient in it. Also, the darker your skin, the more sunlight you need to keep vitamin D3 at healthy levels. This is because the extra melanin found in darker skin slows the absorption of vitamin D3. Some studies suggest that the time of day when you receive sunlight affects how well your body absorbs vitamin D3. While many experts advise people to avoid sunlight between the hours of 10 AM and 2 PM or 3 PM to help protect their skin from cancer, data shows the body actually absorbs vitamin D3 better during this time.
The Difference Between Vitamin D2 and Vitamin D3
There are two forms of vitamin D: Vitamin D2, or ergocalciferol, is commonly found in foods. Vitamin D3 is made by the body naturally when skin is exposed to the sun. Although there is some debate, most experts currently believe that the best form of vitamin D supplement to take is vitamin D3. It's thought that D3 is more natural and easier for the body to absorb. Also, the body does not allow as large a concentration of D3 to circulate in the bloodstream as it does D2, so it's considered safer.
Vitamin D Foods
Oily fish like salmon, codfish, mackerel, and blue fish are great natural sources of vitamin D. Fortified foods -- such as milk and cereal -- along with egg yolks and raw shiitake mushrooms also contain vitamin D.
Vitamin D3 and Acne
There is some debate about whether vitamin D3 works to treat acne. The Vitamin D Council website states that lack of sunlight may increase acne, and some people notice their acne worsening during the winter and improving during the summer. Still, there aren't any clinical studies supporting the use of vitamin D3 for acne. There's also very little evidence supporting the use of vitamin D in preventing acne. However, some anecdotal reports claim that acne improved after taking vitamin D supplements or applying it (in oil form) to their skin.
Vitamin D3 Levels and Weight
Recent studies show that people who are overweight may have higher levels of vitamin D. The reason is thought to be because vitamin D is an oily substance that tends to get stored in the body's fat tissue. So, the more body fat you have, the more easily the body can store vitamin D. If you are underweight, your levels may be lower than you'd expect because you have less body fat in which to store extra vitamin D.
Vitamin D3 Warnings
Talk to your doctor before taking vitamin D3 if you:
You are taking the weight-loss drug Alli or Xenical (orlistat)
Pregnancy and Vitamin D3
It's unclear whether vitamin D3 might harm your unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant before taking this medication. You should also tell your doctor if you are breastfeeding or plan to breastfeed. Vitamin D3 passes into breast milk and is therefore not recommended for breastfeeding mothers.