|
How Much ‘D’ Do I Need?
Posted: 5/14/2009 5:33:00 AM
Studies are emerging almost weekly about vitamin D’s role in protecting our health, and it goes way beyond its ability to help build strong bones. Cancer, diabetes, autoimmune diseases such as MS and rheumatoid arthritis, and even depression are on vitamin D’s list of diseases it may offer protection against. These new findings have many health experts questioning the adequacy of current vitamin D recommendations.
The Sun Source
You would think we’d all have adequate vitamin D levels because one of the best sources is from sunshine. Something everyone has access to, right? Well, that’s not always the case. Here are some factors contributing to our less than optimal vitamin D levels:- Modern day work habits, leisure time spent indoors and obesity can contribute to low levels of vitamin D. Obesity itself appears to reduce the body’s ability to make vitamin D from sun exposure.
- Those who reside in northern climates in the winter months are at risk for low vitamin D levels.
- Adults over age 50 are less efficient at synthesizing vitamin D from sunlight. Elderly with disabilities spend more time indoors further reducing their ability to make enough vitamin D.
- People with darker skin tones have more melanin which reduces their ability to produce vitamin D from sunlight.
- Exclusively breastfed babies are at risk for low vitamin D levels because human breast milk is not a good source of vitamin D. In addition, babies are often sheltered from the sun and have limited exposure through the use of sunscreens and protective clothing. The American Academy of Pediatrics now recommends that exclusively breastfed babies should receive 200 IU supplemental vitamin D within the first two months of life.
- Smog, cloud cover and sunscreen also reduce vitamin D synthesis in the body.
People with fair skin need only 10-15 minutes of direct sun exposure 2-3 times a week without sunscreen, but those with darker skin tones will require a little more time in the sun. This does not mean people can bake in the sun for hours at a time to “improve their health”. Experts still recommend using sunscreen and taking the proper precautions when in the sun for extended periods of time to help reduce the risk of skin cancer and premature aging. The average person makes about 20,000 IU of vitamin D after 20 minutes in summer sunshine, which is many times more than current government recommendations for vitamin D.
Vitamin D Recommendations
There is currently no RDA established for vitamin D. The Institute of Medicine only has determined the adequate intake (AI) required to maintain normal calcium metabolism, one of vitamin D’s many jobs, and the amount needed to prevent rickets and osteomalacia, diseases that weaken the bones. Current recommendations are 200 IU for everyone up to age 50, including infants, children, men and women and during pregnancy. It goes up a bit after age 50 to 400 IU per day and after age 70 your adequate daily intake is 600 IU.
In light of recent vitamin D findings, many health professionals believe these amounts are too low for disease prevention and optimal health. According to the Vitamin D Council, they expect the future RDA for healthy people to be at least 1000 IU per day. Up to 2000 IU per day is a safe dose for those at risk of low vitamin D levels due to inadequate sun exposure or from a reduced ability to digest fat properly because of pancreas or liver problems, celiac disease or crohn’s disease. Testing vitamin D levels may indicate the need for much higher dosages. Most multivitamin and mineral supplements provide 400-800 IU per serving.
A recent review of research reported that the tolerable upper intake level for oral vitamin D3 should be increased from the current tolerable upper intake level of 2000 IU to10,000 IU. This is quite a jump from the old recommendations. The tolerable upper intake level is the maximum one should take to reduce the risk of toxicity. And no, you cannot make toxic amounts of vitamin D from sun exposure alone…you’ll just get a sunburn!
Vitamin D Testing
Rather than guessing about your vitamin D levels, consider asking your doctor to run a test. While many nutrition-oriented physicians are already doing this to promote optimal health in their patients, many conventional doctors test vitamin D levels only when bone disease or osteoporosis is a concern. If vitamin D levels are low, much higher doses of vitamin D supplements would be required. It’s best to be under the care of a knowledgeable health care professional when taking high doses of vitamin D in order to raise low levels.
There are two types of tests available for checking vitamin D levels. Make sure your physician is using the 25-hydroxyvitamin D test, also known as 25(OH)D, which is more strongly associated with general health. You don’t just want “normal” levels you want your levels to be optimal, meaning best for your overall health. Optimal test result levels range from 35–65 ng/mL. If your levels fall below 35, you and your doctor will need to develop a vitamin D plan to increase your levels through safe sun exposure, supplements and food sources of vitamin D.
Best Vitamin D Sources Other than the Sun
There really are few natural food sources of vitamin D, especially foods that appeal to the masses. Cod liver oil is the best natural source. One tablespoon provides roughly 1300 IU of vitamin D. Other food sources include salmon, mackerel, tuna, and fortified foods such as milk and some juices and breakfast cereals. Liver, eggs and some cheeses also provide a small amount of vitamin D. As vitamin D’s popularity increases, there will probably be more foods fortified with it.
Vitamin D supplements will likely be the best way for many to raise low vitamin D levels. There are two types of vitamin D that can be found in supplements and fortified foods, vitamin D2 and D3. When shopping, look for vitamin D3, also known as cholecalciferol. This form is obtained from natural animal sources of vitamin D and is what is formed from sun exposure. Studies suggest it is the more potent form of the vitamin.
If vitamin D’s potential holds true, routine testing of vitamin D levels will be as normal as having blood pressure checked. In the mean time, get a little sunshine, look at how much vitamin D you are getting from vitamins and in the foods you eat and ask your doctor to check your levels so you can be on your way to optimal health!
References:
Office of Dietary Supplements
Mayo Clinic
Annual meeting of the American Association for Cancer Research
16 April 2007, Abstract "Vitamin D: Sunshine, Diet and Supplements - Cancer Prevention and Therapy" Authors: D.L. Trump, M. Fakih, I. Chung, C.S. Johnson
Vitamin D Council
ENdocrinol Metab. 2004 Nov; 89(11): 5387-91
|
|
 |
| 10367 San Pablo Ave, El Cerrito, CA 94530 |
| 1336 Gilman Street, |
|
Berkeley, CA 94706 |
| 510-526-1155 EC |
| 510-526-2456 BK |
 |
Email our Store |
|
STORE HOURS |
| Mon |
9am - 8pm |
| Tue |
9am - 8pm |
| Wed |
9am - 8pm |
| Thu |
9am - 8pm |
| Fri |
9am - 8pm |
| Sat |
9am - 8pm |
| Sun |
9am - 8pm |
| | |
|
|
Back
