Are You Getting Enough Vitamin D? Probably Not.
January 17, 2018 | Published by Dr. Eric Bakker
Vitamin D is a fat-soluble vitamin that is known as the “sunshine vitamin.” Unlike many vitamins, Vitamin D is naturally present in only a very few foods, such as certain seafoods (sardines, shrimp), eggs, and fortified milk. It is also produced inside your body when ultraviolet rays from sunlight strike your skin and trigger vitamin D synthesis. There are many reasons why you need to know about this amazing vitamin, which is also viewed as a hormone.
Vitamin D: Much More Than a Vitamin
Vitamin D is so much more than something that helps produce strong bones. In fact, vitamin D produces multiple effects, including the repair and maintenance of every cell, as well as having the complex action of a steroid hormone that serves multiple gene-regulatory functions in your body. Your body’s complex DNA is activated by Vitamin D.
So far, scientists have found over 3,000 genes which are regulated by vitamin D. Nearly every single cell in your body contains receptors which respond to Vitamin D. No other vitamin has been found to have such a complexity of action in your body.
Which Form of Vitamin D is Best?
There are 5 different D vitamins, form Vitamin D1 to Vitamin D5. The most common are Vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol). One of these is natural, and the other is synthetic. Vitamin D3, the natural version, is the preferred form. Here are a few reasons why:
- D3 gets converted almost five times faster than D2 to its active form.
- Studies have shown that D3 is a more potent form of vitamin D.
- D2 has a shorter shelf life, and its metabolites bind with protein poorly, making it less effective.
Vitamin D Deficiencies More Common Today
Vitamin D deficiencies are becoming much more common today with people spending more time inside and consuming fewer foods containing sufficient amounts of vitamin D. Children in particular have been shown to have insufficient Vitamin D.
There has been some concern that underexposure to sunlight in older people, particularly if they live in northern regions, may put them at risk for low levels of vitamin D. A 1998 study suggests that vitamin D deficiency may be a significant problem in the general U.S. population, even among younger adults. Experts note that adults may need higher daily amounts than the RDA suggests. Exposure to sunlight for about 15 to 20 minutes at mid-morning or mid-afternoon three times a week is also recommended for most people who live in temperate climates.
Who May Need Extra Vitamin D to Prevent a Deficiency?
Many people older than 50 are thought to have a higher risk of developing vitamin D deficiency. The ability of skin to convert vitamin D to its active form decreases with age, and the kidneys (which help convert vitamin D to its active form) tend to reduce in function on average 1-2% per year after a person turns 50. Children need careful vitamin D assessment like adults, but are often overlooked as far as Vitamin D testing is concerned at the doctor’s clinic.
It is very important for those who spend lots of time inside to go out and get sunshine very regularly, preferably every day. If you are unable to meet your daily dietary need for Vitamin D, you may need to supplement with a quality vitamin D3 supplement.
Summary of Those Who May Need More Vitamin D
- Those with frequent muscle aches and muscle weakness
- Those who experience frequent falls, particularly among older persons
- Those who experience bone pain and/or frequent bone fractures
- Children with stunted growth
- Children with asthma (especially severe asthma)
- Those with impaired cognitive function, especially older persons
- Those with lowered immunity
- Those with chronic low energy and fatigue
- Those with chronic depression, particularly among older persons
- People who have an autoimmune disorder
- Those with a lack of exposure to sunlight for any reason, including geography, use of sunscreen, or wearing of protective clothing
Individuals who have reduced ability to absorb dietary fat (fat malabsorption) may need extra vitamin D, as it is a fat-soluble vitamin. Some causes of fat malabsorption are pancreatic enzyme deficiency, Crohn’s disease, gallbladder dysfunction, cystic fibrosis, celiac disease, liver disease, surgical removal of part or all the stomach, and small bowel disease.
Vitamin D – Best Food Sources
Vitamin D is found in a narrow range of foods. Good food sources are oily fish and eggs. Other (non-recommended) food sources include fortified foods such as margarine, breakfast cereals and powdered milk.
|Salmon||100 grams||411 iu|
|Prawns (shrimp)||100 grams||162.39 iu|
|Sardines||1 can (80 grams)||250.24 iu|
|Cow’s milk (2%)||1 cup (250ml)||97.60 iu|
|Cod (baked, steamed)||100 grams||63.50 iu|
|Egg (whole, boiled)||1 egg||22.88 iu|
In 1998, the Adequate Intake (AI) levels in USA for vitamin D for adults, in micrograms (mcg) and International Units (IUs) were:
5 mcg* or 200 IU
5 mcg* or 200 IU
|Ages 51 – 69||10 mcg* or 400 IU||10 mcg* or 400 IU|
|Ages 70 +||15 mcg* or 600 IU||15 mcg* or 600 IU|
|*1 mcg vitamin D = 40 International Units (IU)|
Vitamin D Dosage and Potential Toxicity
The Food and Nutrition Board of the American National Research Council states that 2,000 IU/day is the safe upper limit for the general population, although others have suggested that the safe upper limit may be as high as 4,000 to 10,000 IU/day. Published cases of vitamin D toxicity all involve intakes of at least 40,000 IU/day.
My advice for you is to be careful when using oral vitamin D therapy, and to make certain that you have your blood levels checked regularly. While vitamin D has enormous potential for improving your health, it has significant potential to worsen it, if used improperly.
Infants can be affected in particular by daily amounts higher than 1000 IU, and in children and adults, sustained daily amounts over 50,000 IU can cause weakness, anorexia, vomiting, diarrhea and mental changes. Because Vitamin D is a fat-soluble vitamin and tends to build up in your body, you will need to be particularly careful. I recommend for optimal results that you remain under the care of a skilled healthcare professional with regards to your vitamin D requirements.
Vitamin D – The Bottom Line
Based on studies showing the impact of supplemental D3 intake on blood levels of hydroxyvitamin D, I believe that the vast majority of adults and children will not be able to achieve optimal vitamin D status from food intake alone. Exactly how much vitamin D3 supplementation each individual may need, and the frequency of blood testing, should be determined with the help of your healthcare professional. Your healthcare professional can help evaluate your personal health history factors and can also monitor the impact of your vitamin D supplementation.
It is very difficult to make a firm and fast public health recommendation for vitamin D that is guaranteed to meet the exact and optimal requirements of each individual, because personal health history and an individual’s exposure to sunlight play such an important role in determining each individual’s needs.
About the Author: Eric Bakker B.H.Sc. (Comp.Med), N.D, R.Hom. is a highly experienced naturopathic physician who has been in clinical practice for 27 years. Eric is passionate about improving people’s lives through proven wellness and lifestyle principles, natural medicine practice as well as public and professional practitioner education. Eric specializes in candida, psoriasis, as well as adrenal fatigue, thyroid and digestive disorders. Dr. Bakker has written one of the most comprehensive books on yeast infections called Candida Crusher. He has also written what may well be the most comprehensive Natural Psoriasis Treatment Program available. You can find more articles by Dr. Bakker on his blog at www.ericbakker.com.
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