11/29/2011 3:31:36 PM
Reaching and maintaining an adequate vitamin D level is one of the most important issues in health at present. We are well into days of shorter sunlight in the Northern hemisphere, and with an abundance of new research looking at the optimal vitamin D level for health, it is necessary for me to revisit the topic. The American Heart Association held their annual conference two weeks ago and vitamin D received a lot of attention. vitamin D deficiency was repeatedly linked to poor cardiovascular health within the general population, and in distinct groups such as healthy postmenopausal women, African Americans, and men with hypertension.
One of the most interesting studies presented at the AHA conference was titled, “Vitamin D Excess Is Significantly Associated with Risk of Atrial Fibrillation” because it calls attention to the need to ensure optimal vitamin D status, while not overdosing and reaching a possibly toxic level. The upper limit is still being established, but there is evidence that 100 ng/ml of vitamin D3 should not be exceeded for any length of time. That was the level of vitamin D that was associated with increased risk of atrial fibrillation in 132,000 Americans who participated in the study, which was set up to measure the relationship between vitamin D status and various health issues including diabetes, degenerative disease, coronary artery disease, and depression. The participants in the study were given supplemental vitamin D during the study period.
The study defined vitamin D status based on blood serum measurements as follows:
Definition of Vitamin D Status / Vitamin D Levels
Low Under 20 ng/ml
Low-Normal Between 21–40 ng/ml
Normal Between 41–80 ng/ml
High-Normal Between 81–100 ng/ml
Excess Over 100 ng/ml
Take note that participants with vitamin D levels between 81 and 100 ng/ml had a 36 percent lower risk of hypertension compared to those classified as deficient (below 20 ng/ml). Additionally, participants with levels between 61 and 80 ng/ml had a 52 percent reduction in diabetes compared with those who were deficient. The vast majority of participants had vitamin D levels that were below excess (100 ng/ml), but a small number (291 people, or 0.22 percent of the population) had a vitamin D measurement over 100 ng/ml. Of that group with vitamin D over 100 ng/ml, there was a 2.5 times greater risk of atrial fibrillation compared to those below 100 ng/ml.
Atrial fibrillation is an irregular heartbeat, which is more common as people age. It occurs when the electrical impulse from the heart does not travel in an orderly fashion through the atria. Rather, many impulses begin at the same time and cause a disorganized heartbeat. Regular atrial fibrillation can be influenced by a number of health issues including heart problems, hypertension, and lung disease. It’s unclear if the increased association of atrial fibrillation with excess vitamin D levels was due to the vitamin D or another health concern.
A few things are clear from this study that need to be highlighted:
1) Vitamin D deficiency and insufficiency (below 40 ng/ml) are linked to poor health and the development of a number of health problems.
2) People process supplemental vitamin D differently, meaning that any two individuals who are given 5,000 IUs of vitamin D a day, for example, may have very different blood serum vitamin D levels.
3) It is necessary to regularly test blood vitamin D levels and adjust your vitamin D intake according to your current level.
Before I provide guidelines for replenishing and managing vitamin D levels for optimal health, I will briefly review additional evidence that suggests vitamin D levels over 100 ng/ml is excessive and possibly a source of increased health risks.
Accidental Overdose of Vitamin D Linked to Health Problems in Two Case Studies
A new case study in the Annals of Pharmacotherapy reported that a 70-year-old healthy female was given an incorrect vitamin D dose by her pharmacy (incorrectly prescribed 50,000 IUs daily when she was supposed to take 1,000 IUs daily) because she had a low vitamin D measurement of 34 ng/ml. After three months of taking the excessive dose every day, she developed acute kidney injury. Other symptoms included slurred speech, unstable gait, increased fatigue, and excessive calcium levels.
Vitamin D is instrumental in the body’s ability to absorb and regulate calcium homeostasis, which is the reason for the high calcium. The patient was hospitalized and her vitamin D levels were measured at 194 ng/ml—way over the 100 ng/ml suggested cut-off limit. Supplementation was discontinued and once her symptoms stabilized she was discharged from the hospital. Her vitamin D levels quickly decreased to below 100 ng/ml and were measured at 40 ng/ml after five months.
A second case study in Consult Pharm identified an 84-year-old woman who was prescribed a vitamin D supplement of 50,000 IUs weekly for being vitamin D deficient with a level of less than 7 ng/ml. The prescription was incorrectly filled and the patient was given 50,000 IUs daily for two months resulting in a vitamin D measurement of over 100 ng/ml. Symptoms included decreased appetite and significant weight loss. Once the error was identified the patient discontinued use, vitamin D levels quickly dropped back down to adequate level at which point proper supplementation was started.
Researchers from these studies caution that despite common vitamin D supplementation, excessive vitamin D levels or “hypervitaminosis” is “rare and generally only in the setting of gross excess of vitamin D” supplementation. They also stress the need for regular individual testing of vitamin D because it appears to be processed differently by each individual such that a seemingly high dose may not be effective at raising blood levels for everyone.
Extreme Overdose Causes Health Problems and High Serum D
Very excessive vitamin D intake appears to cause serious health problems and indicates a possibly lethal dose. A case study in the Oman Medical Journal documented ten cases in Kashmir, India, (an area with chronic vitamin D deficiency) of vitamin D overdose and toxicity. Concern with low vitamin D in the area led patients to take excessive amounts of vitamin D. Ten patients ingested a dose of vitamin D that ranged from 3.6 million IUs to 210 million IUs a week over periods ranging from one to four months. The patients’ serum D levels ranged from 100 ng/ml to 306 ng/ml. Take note that the specific dose taken by participants did not dictate a vitamin D serum level, nor did the lower doses equal lower serum levels. This provides more evidence that individuals process supplemental vitamin D differently and regular testing is critical.
Overdose symptoms that were reported included nausea, vomiting, weakness, altered consciousness, hypertension, hearing loss, and excessive calcium levels, among others. It is not clear from the study why patients were overdosing on vitamin D to such an extreme degree, but it is clear that there is an upper limit to healthy intake. Researchers call for careful monitoring of blood vitamin D levels by doctors, patients, and caregivers to avoid such overdoses.
Dose of 2,000 IUs Daily Not Sufficient in Seniors
A recent study in Molecular Nutrition and Food Research indicates that a daily vitamin D dose of 2,000 IUs may be too low. This evidence is particularly important because 2,000 IUs is a common recommendation for adults. This study found that a daily dose of 2,000 IUs for five months effectively raised blood vitamin D level into the adequate range in nursing home patients.
Overall patients’ levels were still on the low side, with the average level being in the range of 40 ng/ml. No patients had symptoms of toxicity and none had levels over 100 ng/ml. Researchers suggest 2,000 IUs is the lowest minimal dose for elderly individuals and that all nursing home patients without a contraindication should be routinely given 2,000 IUs of vitamin D daily. Naturally, they should also have their blood vitamin D levels tested regularly to support optimal health.
Five Steps To Manage Your Vitamin D Levels
1. Get a Blood Value
Start by getting your vitamin D blood level measured. This is essential because it will give you a baseline measurement that will dictate the amount of vitamin D you should take. For example, if you have are deficient, you’ll need to use a dosing system to raise vitamin D levels. Then, I suggest a maintenance dose that is smaller. Also, remember that blood vitamin D levels often vary seasonally due to differences in the amount of sun you are exposed to.
2. How to Get Vitamin D Measured
Your doctor should be able to measure your vitamin D. It is covered by most insurance companies, so getting it measured should not be difficult. If you don’t have insurance or prefer to get your test done privately, various lab testing companies can measure vitamin D for you. For example, the company Life Extension offers a vitamin D blood test...
Independent tests range in price from $12 to $40 in most countries. I suggest testing vitamin D once a month—this does not make you a bad person, and it allows you to adjust the dosage much more effectively.
3. Raise Levels to 32 ng/ml (Standard Units used in U.S.) or 80 nmol/L (International Units)
If you’re levels are below 32 ng/ml, you will want to use a dosing protocol to initially raise your vitamin D levels.
For some physiological reason yet to be fully explained by science, a large bolus dose twice a week seems to work better than the same dose divided over 7 days. A “bolus” dose is one that is prescribed to raise a blood compound such as vitamin D to an effective, therapeutic level. In other words, 35,000 IUs twice a week works better than 5,000 IUs every day for 7 days. Interestingly, the biweekly bolus dose appears to be more effective than even a much larger daily dose such as 10,000 IUs every day for 7 days.
I learned this trick from Dr. Tim Hall from Colorado Springs in May 2009 when he attended the BioSignature seminar in New York City. I have applied his tip with myself and my clients and found that it replenishes vitamin D levels more quickly than dosing it every day.
4. Adjust Vitamin D Intake According to Blood Tests
Adjusting vitamin D intake based on blood tests may seem tricky, but let me provide an example. Let’s say I have a French Canadian weightlifter name Joe-Louis Buveuxdepepsi who presents with a vitamin D level of 14 nmol/L (about 6 ng/ml), which is abysmal. I would suggest taking 50,000 IUs twice a week for 8 weeks, and then recheck his levels. That would be 10 capsules of D3 my Excellence twice a week. If he is now at, let’s say 62 nmol/L (24.8 ng/ml), I would drop the dose to 35,000 IUs twice a week for a month, and then recheck the levels.
Remember, people’s bodies process vitamin D at various rates. Plus, the status of a number of nutrients including magnesium and zinc will influence your ability to process and raise vitamin D through supplementation. It’s essential that you test your vitamin D before taking high doses. Vitamin D toxicity is very rare, but clearly from the evidence presented above, we know that it does occur, with negative health effects. Errors in supplementation are the most common cause, indicating the importance of a reputable supplement provider and a reliable physician. Take note that in all of the cases of toxicity, participants simply needed to discontinue vitamin D intake, symptoms were reversed and health status returned to pre-overdose levels.
5. Test Magnesium and Zinc Too For Best Results
It is a wise practice to measure red blood cell levels of magnesium and zinc at the same time that you test your vitamin D. These are essential minerals, and low levels of either will lead to poor health and a vast array of complications including endocrine imbalance, insomnia, anxiety, and poor energy. If you do not rapidly replenish vitamin D levels from the above dosing protocol, I suggest increasing the dose of magnesium, zinc, and vitamin E.
Zinc is particularly important for optimal testosterone levels, and it is synergistic to all nutrients, meaning increasing your zinc intake can help you elevate your blood vitamin D status. Adequate magnesium is critical for calcium and vitamin D absorption, which is the reason magnesium deficiency, may hinder vitamin D processing and effectiveness in the body. Additionally, there is evidence of a relationship linking low vitamin D with low vitamin E, especially in special populations such as pregnant women or the elderly.
Vitamin D is a fat-soluble vitamin best known for its roles in preventing rickets and maintaining proper levels of calcium in the blood. The 'Sunshine Vitamin' is generally acquired by the body in two ways - exposure to the sun's ultraviolet (UV) rays and dietary intake.
Vitamin D supplementation helps to prevent Vitamin D deficiency which is important as the vitamin is a factor in the maintenance of good health.
Furthermore Vitamin D helps in the
• development and maintenance of bones.
• development and maintenance of teeth.
• absorption and use of calcium and phosphorus.
It has generally been thought that if you get enough time in the sun and eat a diet with foods like Vitamin D fortified milk, deficiency will not be a problem. However, many factors come into play when it comes to your body receiving UV exposure to the sun and processing that into vitamin D in the body.
Things like time spent in the sun, age, genetics, use of UV-blocking sunscreens, and even where you live can all have an effect.
Maintenance of Good Health
Vitamin D is an important factor in the maintenance of good health. Furthermore Vitamin D helps in the
development and maintenance of bones and teeth, and the absorption and use of calcium and phosphorus.
Anti-Ageing
Anti-Ageing Researchers theorise that inflammation and oxidative stress play roles in the ageing process, and that Vitamin D decreases the levels of compounds that may cause inflammation in the body.
Findings from a study published in 2007 suggest that Vitamin D may play a part in slowing the ageing process and the onset of age-related diseases. They concluded that:
“The results demonstrate for the first time that people who have higher levels of Vitamin D may age more slowly than people with lower levels of Vitamin D...”]
For a must-read article on vitamin D, check out Kaisa Jaakola’s article Let’s Talk About Vitamin D.
References:
Smith, M., May, H., et al. Vitamin D Excess is Significantly Associated with Risk of Atrial Fibrillation. Circulation. November 2011. Special Supplement from Annual American Heart Association Conference. http://circ.ahajournals.org/cgi/content/meeting_abstract/124/21_MeetingAbstracts/A14699?sid=d8af4ab7-eb16-4360-8e52-179868c1e439
Schwalfenberg, G., Genuis, S. Vitamin D Supplementation in a Nursing Home Population. Molecular Nutrition and Food Research. August 2010. 54(8), 1072-1076.
Koul, P., Ahmad, S., et al. Vitamin D Toxicity in Adults: A Case Series from an Area with Endemic Hypovitaminosis D. Oman Medical Journal. 2011. 26(3), 201-204.
Carlton, S., Clopton, D., et al. Vitamin D Deficiency: Appropriate Replenishment Therapies and the Effects of Vitamin D Toxicity. Consult Pharm. March 2010. 25(3), 171-177.
Jacobsen, R., Hronek, B., et al. Hypervitaminosis D Associated with a Vitamin D Dispensing Error. Annals of Pharmacotherapy. October 2011. 45(1), e52.
Asemi, Z., Taghizadeh, M., et al. Assessment of the Relationship of Vitamin D with Serum Antioxidant Vitamins E and A and Their Deficiencies in Iranian Pregnant Women. Saudi Medical Journal. October 2010. 31(10), 1119-1123.
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