How Much Vitamin D Do You Really Need to Take?
On November 3 at the University of Toronto in Ontario, Canada, noted doctors Cedric Garland and Tracey O’Connor are running a seminar on how vitamin D can be used to prevent breast cancer — as well as infectious diseases, type 1 diabetes, hypertension, colon cancer, and falls in the elderly.
The conference will look at the current research and practice with vitamin D to enable everyone to take action today based on what’s known to solve the deficiency epidemic, and to start the prevention of many diseases.
General Information about Adult Vitamin D Requirements
Currently, the U.S. RDA for vitamin D is 400 IU (international units) for the majority of the population. (IU is frequently shortened to just “units.”) This dose was recommended to prevent rickets, which works well, but does nothing to give the far more important protection from cancer, heart disease and infections.
To achieve the healthy blood levels in the graph below, most adults will need about FIVE THOUSAND units of vitamin D every day, but some worry that if they are in the sun that they will overdose on vitamin D.
This is not typically the case, and here’s why: When you’re exposed to the sun, the UVB rays cause vitamin D to be produced in your skin while the UVA rays in the sunlight will tend to destroy excessive levels of vitamin D circulating in your body. It is somewhat of a natural failsafe mechanism that prevents overdosing.
Please remember that the ONLY way to know for sure is to get your blood level tested.
Current RDA Guidelines for Vitamin D are Outdated and in Light of New Research New Recommendations are being made for Daily Intake for Optimal Health
Based on the most recent research, the current recommendation is 35 IU’s of vitamin D per pound of body weight.
So for a child weighing 40 pounds, the recommended average dose would be 1,400 IU’s daily, and for a 170-pound adult, the dose would be nearly 6,000 IU’s.
However, it’s important to realize that vitamin D requirements are highly individual, as your vitamin D status is dependent on numerous factors, such as the color of your skin, your location, and how much sunshine you’re exposed to on a regular basis.
So, although these recommendations may put you closer to the ballpark of what most people likely need, it is simply impossible to make a blanket recommendation that will cover everyone’s needs.
So how do you ensure optimal vitamin D levels for yourself, your child, and aging parents?
Blood Testing is the ONLY Reliable Way to Determine How Much Vitamin D You or Your Child Needs
Step 1: Make Sure You Use the Correct Test
The correct test your doctor needs to order is 25(OH)D, also called 25-hydroxyvitamin D, which is the better marker of overall D status. This is the marker that is most strongly associated with overall health.
Step 2: Determine Your OPTIMAL Level of Vitamin D
The OPTIMAL value that you’re looking for is 50-65 ng/ml.
This range applies for everyone; children, adolescents, adults and seniors.
These ranges are based on healthy people in tropical or subtropical parts of the world, where they are receiving healthy sun exposures. It seems more than reasonable to assume that these values are in fact reflective of an optimal human requirement.
Keeping your level in this range, and even erring toward the higher numbers in this range, is going to give you the most protective benefit. And the way you maintain your levels within this range is by getting tested regularly – say two to four times a year in the beginning, and adjusting your vitamin D intake accordingly.
Are Oral Vitamin D Supplements Your Best Choice?
The best way to optimize your vitamin D levels is through appropriate safe sunshine. However, there are many times when it can be nearly impossible to get enough sun.
The darker your skin is, the farther away from the equator you are, and the further away you are from the summer months, the less likely it is that you will produce adequate vitamin D levels from sun exposure alone.
In these cases, supplementing with vitamin D is acceptable, but I strongly recommend monitoring your blood levels regularly when taking oral vitamin D supplements to make sure you’re staying within the optimal range.
Only Supplement with the Right Kind of Vitamin D
There is one other thing you need to be aware of if you choose to use an oral vitamin D supplement and that is that there are basically two types – one is natural and one is synthetic.
- The natural one is D3 (cholecalciferol), which is the same vitamin D your body makes when exposed to sunshine
- The synthetic one is vitamin D2, which is sometimes called ergocalciferol
Once either form of the vitamin is in your body, it must be converted to a more active form. Vitamin D3 is converted 500 percent faster than vitamin D2, and is clearly a better alternative.
Vitamin D2 also has a shorter shelf life, and its metabolites bind with protein poorly, making it less effective. Studies have even concluded that vitamin D2 should no longer be regarded as a nutrient appropriate for supplementation or fortification of foods (although it continues to be used). So if you choose to use vitamin D supplements make sure it is in the form of vitamin D3.
Please be aware that nearly all the prescription-based supplements contain synthetic vitamin D2, so if you receive a prescription for vitamin D from your doctor, you’re most likely receiving the inferior vitamin D2.
If you have any questions please feel free to ask- and make sure your getting the proper Vitamin D!