Vitamin D Deficiency is rampant. I started testing Vitamin D level in my patients 20 years ago. Results were startling! More than 90% of my patients turned out to have Vitamin D deficiency. These are individuals living in sunny southern California with a 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.
Symptoms Of Vitamin D 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 to assess your Vitamin D level is to get a blood test.
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.
Watch Out for the Units Used By the Laboratory
Different laboratories report Vitamin D level in different units. 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.
Unfortunately most physician don’t pay attention to the units of the test, which can lead to inaccurate interpretation. For example, your laboratory reports 25 (OH) Vitamin D to be 40 nmol/L. Your physician simply looks at the number 40 and interprets your Vitamin D level to be good. In his mind, it’s more than 30, so you’re fine. In fact, your Vitamin D is low because a level of 40 nmol/L is equal to 16 ng/ml.!!
What Is the Normal Range of Vitamin D?
The lower limit of normal range for 25 (OH) Vitamin D should be 30 ng/ml or 75 nmol/L.
The upper limit of normal should be 100 ng/ml or 250 nmol/L.
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. Also, fifteen minutes of sunshine a day is insufficient to get a good level of Vitamin D.
It’s also unscientific to make general recommendations about how much sun exposure can provide you with enough Vitamin D. Why? Because 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!
Scientific 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 lifestyle 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
You can get Vitamin D from Four Sources:
- Sun exposure
- Vitamin D supplements
- Ultraviolet lamps . (I never resort to ultraviolet lamps, which are expensive and in my experience, unnecessary.)
Vitamin D from the Sun
Sun is the main natural source of Vitamin D. However, our modern lifestyle prevents us from getting enough Vitamin D from the sun. 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.
Vitamin D From Food Sources
Foods are a poor source of Vitamin D. For example, 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.
Vitamin D Supplements
From a practical standpoint, Vitamin D supplements are an easy and effective way to get adequate levels of Vitamin D.
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, overweight and obese individuals need 15,000 – 20,000 I.U. a day. Why? Because Vitamin D is fat-soluble. Hence, the more fat you have, the more Vitamin D will be trapped there. Consequently, less Vitamin D is available for the rest of the body.
For the same reason, thin people may need only 2,000 – 3,000 I.U. a day.
Formula to Calculate Your Dose of Vitamin D Supplement
Here is a general formula to calculate the dose of Vitamin D supplement:
1000 IU of Vitamin D for every 20 Lbs. of body weight.
For example, if you weigh about 200 Lbs. you will need 10,000 IU per day.
Concerned about Vitamin D toxicity? It is rare. Review of the published cases of Vitamin D toxicity show that Vitamin D toxicity may occur if you take more than 80,000 IU per day of Vitamin D for several weeks. Get the facts about Vitamin D toxicity.
Vitamin K2 with Vitamin D3
Vitamin K2 along with Vitamin D3 helps to incorporate calcium into the bones. Therefore, both of these vitamins are important for bone health. In addition, Vitamin K2 prevents the deposition of calcium into the arterial walls. Therefore, it is important to take Vitamin K2 along with Vitamin D3.
Dr. Z’s Vitamin D3 with Vitamin K2 is a unique combination of Vitamin D3 as 5000 IU and Vitamin K2 (MK-7) as 100 microgram per capsule. 120 vegetarian capsules per bottle. It is made in the USA at a GMP-Certified and FDA-Registered facility from the highest quality ingredients.
For more details about Vitamin D, please refer to Dr. Zaidi’s popular book “Power Of Vitamin D”