I have written before about the dosage of vitamin D that I should be taking, and the toxicity of vitamin D, but here is a new study from the University of Kentucky that indicates that levels of vitamin D that are too low may be associated with brain damage.

The researchers studied animals, so it remains to be seen whether the same effects would be seen in humans. However, I do know that I feel better when I have been able to spend at least some time in the sunshine, so maybe there is a bit of truth here?

Read the rest of this entry

A member of my wife’s family was diagnosed with colon cancer a while ago. We have been looking at the value of various supplements in support of the treatment she is reading. Several studies have linked low vitamin D levels to reduced risk of many diseases, including colon cancer.

My training as a pharmacist warned me that vitamin D can be dangerous if taken at very high levels. What levels are dangerous? I found a study that was published in the journal Anticancer Research in February of this year. The researchers believe that intake of up to 40,000 international units/day are not likely to result in signs of significant toxicity (poisoning). This is a huge dose, and closer reading of the abstract shows that the dose required to get the serum 25(OH)D level above 40 ng/mL was almost 10,000 international units/day.

The full article was available at no charge. So I took a look at it. The authors enrolled more than 3600 patients and measured their 25(OH)D levels. They found that most people were taking less than 500 international unit each day. The authors noted that this is the first analysis of a relation between vitamin D levels and vitamin D supplements measured in a community of patients. The patients were not taking a single brand of vitamin D, so it is not possible to say which brand anyone should take. The study raises a lots of questions, but they made it clear that what was thought to be a high dose a few years ago may actually be what most people need.

Of course, an individual should not be taking the second day without consulting with a physician. There are just too many things that should be considered to be able to suggest a dose that will work for everyone. Some of the things include where you live, how much time you spend in the sunshine, and any dietary sources of vitamin D. Other research has suggested that some diseases may be associated with low levels of vitamin D, but whether the disease or the low vitamin D levels come first is not known.

Vitamin D is found everywhere in the body. It is essential for many body functions. It has been shown to be important in helping to

• Avoid complications of pregnancy
• Avoid Parkinson’s disease
• Maintain cognition (this may help reduce the effects of Alzheimer’s disease)
• Prevent cancer of several types
• Prevent type 1 diabetes, especially in babies
• Increase the risk of heart attacks and stroke
• Increase the body’s ability to fight Clostridium difficile infections (that is a nasty infection that is resistant to many antibiotics. Help avoid it by making sure you wash your hands frequently when visiting someone in hospital)
• Increase your response to exercise
• Increase the chances of migraine (possibly)
• Increased risk of fibromyalgia (a painful condition that has sometimes been linked to chronic fatigue syndrome)

There are probably many other health problems possibly associated with not enough vitamin D in the body. Autism has been suggested by some experts as being related to lack of vitamin D, but there needs to be a lot more research done to confirm the link – it might be that the lack of vitamin D is actually the result of something else.

The problem with all of these possible ill effects of not enough vitamin D is that it takes a long time to show the effects of supplementation with vitamin D on the health problem. There is also disagreement over the type of vitamin that should be used for supplementation.

So, how much vitamin D do I need?

Unfortunately, that is not possible to answer in a post – it all depends. How much vitamin D do you actually have in your body? How much sun to you allow to reach your skin (without sun blocker or clothes)? How dark is your skin? How far north (or south) of the equator do you live (the higher the latitude, the less effective sun exposure is in increasing vitamin D levels). How old are you (older people make less vitamin D)? How much vitamin D do you get in your food?

The answer to the last question is actually easy – not much. The only way to know how much vitamin D you need is to have a health care provider request a lab test for you. Once you know the levels, then you can plan for getting more vitamin D. The majority of people in the higher latitudes do not have enough vitamin D, so I can be fairly certain that you will need more.

Options for increasing vitamin D levels

Really, there are only two ways to increase vitamin D levels:

• More sun exposure
• Supplementation

The sun exposure can be difficult – you need about 15-20 minutes of full sun exposure every day during. As I write this post there has been no sun all day! In doing this, you have to be careful to avoid burning your skin. You may need to increase the time if you are dark skinned, and as you get older. See how difficult it is? The amount of vitamin D you can get from food is limited. Maybe a bit from calcium and vitamin D that is added to some orange juice or milk, but that is not a reliable amount.

Supplementation is easier, but you need to work with your health care provider to determine the dose. You don’t need to use a prescription form of vitamin D. What you can buy at the health food store is usually enough. Just make sure you buy a good brand, and have your vitamin D levels checked. Probably at the beginning and end of winter.

Blood levels of vitamin D

Blood levels should ideally be kept above 15 ng/ml (37.5 nmol/L), but less than 200 ng/ml (500 nmol/L) according to the Office of Dietary Supplements. My physician recommends keeping my levels closer to the lower level to avoid side effects. I take 1000 units per day, but some people may need 10,000 units/day, at least for a short time. It is important to work with your health care provider to determine YOUR correct level of supplements.

I often see questions on various forums and in news articles questioning the value of multivitamins.  There is a lot of evidence in the literature that in some cases individual vitamins have been shown to have this or that effect. Often, there is no effect, although in some cases it another vitamin is beneficial. Other times we read that a combination may show some benefit. Calcium and vitamin D is one example. Why should this be?

There are a couple of reasons why we need to look closely at what vitamins we are taking. Firstly, we need to make sure that they are high quality, that they undergo some kind of testing where the results are publicized, so that we can depend on actually getting what the label says we are getting. The FDA does not routinely inspect the places where vitamins are manufactured. They are concerned with whether those herbal remedies contain some form of the drug contained in Viagra, but under the Dietary Supplement Health and Education Act (DSHEA) of 1994, there is no prelaunch approval process for supplements similar to the process for pharmaceutical drugs. FDA will only act if there are problems reported with a supplement; and usually only if there are a lot of problems reported. Particularly if people have died.

The second reason we need to look closely at the vitamins we are taking is that some of them will only work if they are taken together. Like calcium and vitamin D, that I mentioned above. Several of the B vitamins work best if they are taken with other B vitamins. This is a problem with clinical trials – if the trial is of a single vitamin taken alone, how do we know that it will be used effectively by the body? We don’t.

Good combinations of vitamins are quite ‘expensive’ in money terms. However, we can read that the food that we eat is of lower nutritional quality than it was 30 years ago (I did a few weeks ago). This means that we have to replace some of that quality with a good nutritional supplement. Also known as multivitamins. These are different from the herbal ‘dietary supplements’. The manufacturing quality can be controlled to ensure that the amount of each vitamin is close to the amount stated on the label. Did you know that there are manufacturing tolerances for pharmaceutical drugs as well?

So, to ensure that we are getting ‘good’ vitamins, we should pick a company that carries out research into the optimal combinations of vitamins, and manufactures the resulting combinations with as much care as a pharmaceutical company does. That way, we can be sure we are getting value for money.

Do I take vitamin and mineral supplements? Yes. As a result, my blood pressure is lower than the ‘standard’ pressure for my age, I do not have diabetes, and I only rarely visit a doctor other than for check-ups. Could this be the result of eating a healthy diet and exercising? Yes, it probably could. Could it be something in my genes? Sure, but unless I get genetic testing, I am not going to know for sure. Could it be luck? Maybe, but don’t we all create our own ‘luck’ by working hard and eating right? I just prefer the additional insurance that taking vitamins gives me, maintaining Rodshealth at an excellent level.

Think about it.