Vitamin D (the sunshine vitamin) is one of the most important vitamins for our overall health, yet about 77% of Americans are not getting enough. What is Vitamin D, why is it so important to our well being and how do we know if we’re getting enough? Those are just some of the questions we hope to answer in this 2-part post about Vitamin D.
Vitamin D2 or Vitamin D3... Which Form is Better?
There are two types of vitamin D supplements available for over-the-counter purchase, vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). Vitamin D2 is a fungus/yeast-derived product while D3 is synthesized in the lab from animal sources to mimic how our own skin would produce Vitamin D3. Most experts agree that vitamin D3 is the best form as it is the most “natural” form, it binds to receptor sites better, and it’s more potent and stable. Vegetarians or vegans may prefer D2 as it not sourced from animals.
Whichever form you choose, Vitamin D supplements are best absorbed when taken with a large meal.
Why We Need Vitamin D?
The major function of vitamin D is to maintain normal blood levels of calcium and phosphorus. Vitamin D aids in the absorption of calcium, which helps form and maintain strong bones. It is used, alone or in combination with calcium, to increase bone mineral density and maintain healthy bones. Strong research also suggests that vitamin D is helpful in supporting immune function and overall health.
Vitamin D deficiency can cause rickets (skeletal deformities) in children and osteomalacia (weak muscles and bones) in adults.
How Much Vitamin D Do We Need?
While the Recommended Daily Allowance (RDA) of vitamin D for adults up to age 70 is 600 IU (International Units) and 800 IU for those over 70, many experts believe these are too low. According to the National Osteoporosis Foundation:
- Adults under age 50 need 400 to 800 IU of vitamin D daily.
- Menopausal women and adults over the age of 50 are advised to get 800 to 1,000 IU of vitamin D daily.
- If your serum levels of Vitamin D are low, you may require as much as 5,000 IU per day.
It’s always best to speak with your doctor regarding an intake that is appropriate for your specific needs.
Check part two of this post to learn if you’re at risk for Vitamin D deficiency and what you can do to get enough of this important nutrient.
National Institutes of Health
Consumerlab.com (full report requires membership)