Vitamin D Deficiency is rampant. I started testing vitamin D level in my patients 15 years ago. Results were startling! More than 90% of my patients turned out to have vitamin D deficiency. These are the individuals living in sunny southern California with healthy outdoor lifestyle-golf, tennis,hiking, biking……. Many of these patients drink milk and take a multivitamin as well as a calcium tablet that contains vitamin D.
Myths about Vitamin D
Unfortunately, there are a number of myths about Vitamin D.
Myths that I frequently hear that are incorrect:
- I can’t be low in Vitamin D because I drink milk.
- I can’t be low in Vitamin D because I take a multivitamin as well as a calcium tablet that also contains Vitamin D.
- I can’t be low in Vitamin D because I live in sunny southern California.
- I go outdoors 15 minutes a day. Therefore, I should have a good level of Vitamin D
- I read there is a high risk of Vitamin D toxicity if I take Vitamin D.
Health Benefits Of Vitamin D
Vitamin D is important for the health of every organ system in the body.
Here’s a summary:
- Vitamin D is important for the absorption of ingested calcium. If you don’t have enough Vitamin D, you don’t appropriately absorb calcium.
- Vitamin D is important for the health of our bones and muscles. If you are low in Vitamin D, you’re at risk for osteoporosis. You can also develop muscle aches and pains, which often get misdiagnosed as Fibromyalgia or Chronic Fatigue Syndrome.*
- Vitamin D is important for the normal functioning of our immune system.*
- Vitamin D also has anti-cancer properties and may prevent various cancers.*
- Vitamin D may prevent heart disease.*
- Vitamin D may even prevent diabetes.*
- Vitamin D may be helpful for neuro-degenerative disorders such as Autism, Parkinson’s disease and Alzheimer’s disease.
Symptoms Of Vitamin D3 Deficiency
There are no specific symptoms of Vitamin D deficiency. There is a wide variety of non-specific symptoms such as chronic fatigue, muscle aches and pains, impaired immune system, dental fracture, depression—
The best way is to get a blood test to assess your vitamin D level.
Diagnosis Of Vitamin D Deficiency
It’s easy to diagnose vitamin D deficiency: It’s a simple blood test. That’s all! However, it needs to be the right test and must be interpreted properly! And that’s where a lot of problems arise.
What’s The Right Test To Diagnose Vitamin D Deficiency And Why?
Laboratories offer two tests to determine vitamin D level in the blood. In vitamin D deficiency, one of them is low whereas the other one is often normal. Most physicians don’t know the distinction between these two tests and may order the wrong test. Consequently, they may say your vitamin D level is normal, when it’s actually low.
The right blood test to evaluate your vitamin D status is: 25 (OH) vitamin D (25-hydroxy vitamin D ).
The other blood test for vitamin D is 1,25 (OH)2 vitamin D (1,25 dihydroxy vitamin D).This is the wrong test to diagnose vitamin D deficiency! Why?
There are two reasons why 25 (OH) vitamin D and not 1,25 (OH)2 vitamin D is the right test to diagnose vitamin D deficiency.
25 (OH) vitamin D stays in your blood for a much longer period of time (half life of about 3 weeks) compared to 1,25 (OH)2 vitamin D (half life of about 14 hours). Therefore, 25 (OH) vitamin D more accurately reflects the status of vitamin D in your body.
As vitamin D deficiency develops, your body increases production of parathyroid hormone by the parathyroid glands situated in your neck. Parathyroid hormone increases the conversion of 25 (OH) vitamin D into 1,25 (OH)2 vitamin D. Consequently, 1,25 (OH)2 vitamin D level in the blood will stay in the normal range (and can even be high) even if you’re low in 25 (OH) vitamin D.
Why Are The Normal Ranges For 25 (OH) Vitamin D Reported By Some Laboratories Inaccurate?
The normal ranges for vitamin D come from the era when our concern was just to prevent rickets. A small dose of vitamin D is enough to prevent rickets. Therefore, a level of 25 (OH) vitamin D of 10 ng/ml (25 nmol/L) or above was established as adequate to prevent rickets. That’s why some laboratories report 10 ng/ml (25 nmol/L) as the lower limit of the normal range.
However, in recent years our understanding of the effects of vitamin D has dramatically changed. Now, we understand that vitamin D can do much more than simply prevent rickets. In fact, vitamin D is crucial for maintaining many vital functions in the body, such as a healthy immune system and a healthy heart. In addition, an adequate level of vitamin D helps prevent diabetes, osteoporosis and cancer, as discussed earlier.
To achieve these goals, many experts in the field (including myself) recommend a level of 25 (OH) vitamin D to be at least 30 ng/ml (75 nmol/L). Unfortunately, many laboratories continue to report a normal range with the lower limit of 10 ng/ml (25 nmol/L). Now, imagine the following scenario: Your 25 (OH) vitamin D level is 21 ng/ml. Your physician interprets this as normal, because it’s in the “normal range” provided by the laboratory. However, you are actually quite low in vitamin D! This happens all too frequently.
Watch Out For The Units Used By The Laboratory
There is another problem that many physicians are unaware of. Different laboratories report vitamin D level in different units. In the USA and around the world, most laboratories report 25 (OH) vitamin D in one of two ways: either as ng/ml or nmol/L.
The conversion factor from ng/ml to nmol/L is about 2.5. For example, if your level is 30 ng/ml, you multiply it by 2.5 and will get a number of 75 in nmol/L. The lower limit of normal for 25 (OH) vitamin D should be 30 ng/ml or 75 nmol/L.
Now, let’s assume that you are fortunate enough to have a physician who keeps up with the latest information and is proactive about vitamin D supplementation. From attending conferences and reading articles on vitamin D, your physician may simply remember that the lower limit of normal for 25 (OH) vitamin D is 30 (and that’s how most physicians remember – just the numbers, without paying attention to the units).
Here’s another treacherous case scenario: Your laboratory reports your 25 (OH) vitamin D to be 40 nmol/L. Your physician simply looks at the number 40 and tells you your vitamin D is good. In his mind, it’s more than 30, so you’re fine. In fact, your vitamin D is low because in reality, a level of 40 nmol/L is equal to 16 ng/ml.!! He totally forgot to look closely at the units.
Also, note that the upper limit of normal as reported by many laboratories is also inaccurate. The upper limit of normal should be 100 ng/ml (250 nmol/L).
Treatment Of Vitamin D Deficiency
Most physicians do not know how to properly treat vitamin D deficiency. Sad but true. Why? Because it’s not taught during their medical training. Nor do they have much experience in their clinical practice. It’s a new field for them.
What amazes me is the advice given in newspaper articles, such as “Experts recommend either 600 units of vitamin D a day or 15 minutes of sunshine a day is enough to get a good level of vitamin D.” Based on my clinical experience, I believe these recommendations to be incorrect.
Why Are Recommendations On The Daily Dose Of Vitamin D Incorrect?
I check vitamin D level in all of my patients. The majority turn out to be low in vitamin D. Many of them take the recommended dose of 600 I.U. of vitamin D a day. Many of them also go out in the sun at least 15 minutes a day in sunny southern California, yet they’re still low in vitamin D. Based on this kind of sound clinical evidence, it’s clear to me that 600 I.U. of vitamin D a day is insufficient. Fifteen minutes of sunshine a day is also insufficient to get a good level of vitamin D.
Many scientific studies have clearly demonstrated that the current recommended dose of 400-600 I.U. of vitamin D per day is not optimal. An excellent review (1) of these studies was published in the American Journal of Clinical Nutrition. The authors concluded that the beneficial blood level of 25 (OH) vitamin D starts at 30 ng/ml (or 75 nmol/L) and these levels of vitamin D can not be achieved in most patients with the daily recommended dose of 400-600 I.U. of vitamin D.
It’s also unscientific to make general recommendations about how much sun exposure can provide you with enough vitamin D. Why? As discussed earlier in Chapter 4, Natural Sources of Vitamin D, there are many variables that determine how much vitamin D you can get from the sun.
In areas north of 44 degrees N latitude, sun rays are less effective in producing vitamin D in the skin during winter months. The farther north you live, the less effective skin synthesis is from sun exposure.
In the same region, the sun is less intense during winter months. Consequently, skin synthesis of vitamin D decreases during wintertime.
As you grow older, the skin becomes thin and less efficient in synthesizing vitamin D from sun exposure.
The darker your skin, the less efficient it is in forming vitamin D from sun exposure.
If you use sunscreen (like most people in the USA), then your skin can’t form vitamin D even if you live in a sunny area like Los Angeles or Miami.
Obviously, if you stay out of the sun, you can’t form vitamin D in your skin. Many people work indoors and choose leisure activities that are indoors. Similarly, if you cover your entire skin due to cultural reasons (like many women in the Middle-East), you can’t form Vitamin D from your skin, even though you live in a sunny place.
With so many variables determining vitamin D level, how could “spending 15 minutes a day in the sun” be an accurate recommendation? For example, a New Yorker spending 15 minutes a day in the sun will have a different vitamin D level than a Texan. Even in New York, a person with fair skin will have a different vitamin D level than a person with dark skin. A teenager will have a different level than a grandparent. The same New Yorker will have a different level of vitamin D during summer versus winter. You can see why the “15 minutes of sunshine a day recommendation” is flawed. The “one size fits all” approach doesn’t work when you have so many variables!
My Approach To The Treatment Of Vitamin D Deficiency
Over the last fifteen years, I’ve treated thousands of patients with vitamin D deficiency. Based on my own clinical observations, I’ve developed a unique, scientific yet practical treatment approach that works well for my patients. My approach to treat vitamin D deficiency is as follows:
Assess Vitamin D Status
First of all, I assess and treat every person on an individual basis. I order a 25 (OH) Vitamin D level in the blood to assess vitamin D status. This accurately reflects the impact of all of the variables in life style such as geographic location, season, ethnicity, working habits, eating habits, outdoor activities and sunscreen application habits. No guess work. No blind recommendations. To me, this is the most scientific approach in determining one’s vitamin D status!
Aim For An Optimal Level Of Vitamin D
After the lab test, I discuss the results with my patients. As I wrote earlier, the level of 25 (OH) vitamin D should be at least 30 ng/ml (75 nmol/L). Now, you may ask, “But what is the optimal level of vitamin D?” Based on my extensive experience, I believe the optimal blood level of 25 (OH) vitamin D to be in the range of 50-100 ng/ml (125-250 nmol/L). I feel that a vitamin D concentration at this level is important in order to build strong bones, improve immune function, treat aches, pains, chronic fatigue and prevent and treat cancer, heart disease, osteoporosis, tooth fractures, diabetes, high blood pressure, kidney disease and depression and memory loss.
How To Achieve An Optimal Level Of Vitamin D
I discuss with each individual patient various options they can utilize in order to achieve an optimal level of vitamin D.
You can get Vitamin D from Four Sources:
- Sun exposure
- Vitamin D supplements
- Ultraviolet lamps
For an average person, it’s impossible to get a good level of vitamin D from sun exposure or diet alone. For example, according to my experience, a Caucasian person needs to be out in the sun in southern California in a bathing suit for approximately two to four hours a day to get a good level of vitamin D. In the case of a person with dark skin, the duration of sun exposure will be about ten hours a day. Now how many people can have that kind of lifestyle year round?
In my extensive experience of diagnosing and treating Vitamin D deficiency, I encountered only one person with a good blood level of 25 (OH) vitamin D (above 50 ng/ml without taking any supplements). She was a lifeguard with fair skin who spent about four hours a day, five days a week in the sun in her bathing suit. This amount of sun exposure is not only impractical, but also inadvisable. This degree of sun exposure significantly increases your risk for skin cancer, especially if you have fair skin.
Now consider this: One 8 ounce cup of milk has only 100 I.U. of vitamin D. You’d have to drink 20 – 40 cups a day to get a good level of vitamin D. It’s not only impractical, but also inadvisable. Imagine all the calories, the amount of LDL (bad) cholesterol and the natural sugar you’d get from such a huge amount of milk.
A serving of cereal fortified with vitamin D has about 40-80 I.U. of vitamin D. You can imagine how much cereal you’d have to eat to get a good level of vitamin D. There are many negative consequences to eating such a large amount of cereal.
From a practical stand point, I recommend taking advantage of three sources of vitamin D: sun, diet and vitamin D supplements. I never resort to ultraviolet lamps, which are expensive and in my experience, unnecessary.
Vitamin D3 or D2?
Vitamin D2, also known as ergocalciferol, is of plant origin. On the other hand, Vitamin D3, also known as cholecalciferol, is of animal origin. In the natural state, humans synthesize vitamin D3 in their skin upon exposure to the sun. Therefore, I recommend vitamin D3, as this is the physiological type of vitamin D for humans.
How much Vitamin D3?
Most of my patients require a daily dose of 5000 -10,000 I.U. of vitamin D3 to maintain a good level of vitamin D. However, some need up to 15,000 – 20,000 I.U. a day, while others need only 2,000 – 3,000 I.U. a day.
For more details about vitamin D, please refer to “Power Of Vitamin D”
- Bischoff-Ferrari H et al. Current recommended vitamin D may not be optimal. Am J Clin Nutr. 2006;84:18-28.
- Holick MF, Shao Q, Liu WW, et al. The vitamin D content of fortified milk and infant formula. N Engl J Med. 1992;326(18):1178-81.
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