Note: Each week, family physician Regina Chinsio-Kwong, DO from Mission Heritage Medical Group in Laguna Niguel will offer insight on a different vitamin—why you need it, how to incorporate it into your diet and how it affects your health. If you are considering taking any kind of supplement, consult with a medical professional first.
WHAT IT DOES: Vitamin D3 is the main form used by the body and is the most easily absorbed form of vitamin D. It is vital to building strong and healthy bones, because vitamin D helps the body absorb calcium. Vitamin D can also strengthen the immune system, which helps the body fight infection, and maintain muscle strength.
RECOMMENDED DAILY ALLOWANCE: This is measured in International Units (IU). Newborns up to 1 year old should get 400 IU, while children and adults up to age 70, as well as pregnant and breastfeeding women, should have 600 IU. The RDA goes up to 800 IU for people older than 70.
HOW TO INCLUDE IT IN YOUR DIET: Vitamin D3 is produced by the body with exposure to sunlight. However, many people don't get enough vitamin D3 that way due to decreased production in the skin in those who have darker skin tones, or decreased exposure to sun from working indoors or wearing sunscreen. So it's important to get vitamin D3 in your diet. Naturally occurring sources include egg yolks, fatty fish (tuna, salmon) cheese, beef liver and mushrooms. Other foods are fortified with vitamin D3, including milk, cereals, soy drinks and juices. Vitamin D3 is also available in supplements, often under the name cholecalciferol.
HEALTH IMPACT: A lack of vitamin D can put bones at risk for becoming weak and brittle; it can also increase the risk for osteoporosis. Also, some studies point to the possibility that low levels of vitamin D can lead to increased risk for heart attack and high blood pressure. Also, lower vitamin D levels have been found in mood disorders such as depression.
Other studies say vitamin D can also affect cancer, type 1 diabetes, tuberculosis and colds and flu—however, much more research is needed. Be careful, because too much vitamin D can be toxic, resulting in symptoms such as weight loss, constipation, nausea or appetite loss, kidney damage and elevated blood calcium. The latter can disrupt normal heart rhythms and cause disorientation.
Vitamin D3 can also affect, and be affected by, certain medications, including anti-inflammatory corticosteroids (such as prednisone), the weight-loss drug orlistat, a cholesterol-lowering medication called cholestyramine and phenobarbital and phenytoin, which manage epileptic seizures. It's crucial to consult with a health care professional before taking vitamin D supplements and be regularly monitored to ensure it isn't causing problems with your medication.
RECOMMENDED SUPPLEMENT BRANDS: USP labeled supplements such as NatureMade or Kirkland brand products third party tested brands: Metagenics, Vital Nutrients, OrthoMolecular, Pure Encapsulations, Pharmax, Integrative Therapeutics (Nature's Way), Prothera, Designs for Health.
Read more about vitamins: Value of Vitamin Series: B12