Google “vitamin D” and you will get over 12 million entries!
Vitamin D was once thought to be just another vitamin that was important to your health as all the vitamins are. We know it plays a huge role in the regulation and absorption of Calcium, (that’s why you will see it in your Calcium supplements) but it’s just over the past several years that people are “doing extra D” for important added benefits.
A look at Vitamin D
Vitamin D is one of the fat soluble vitamins (the others being A,E and K) found in many food sources. Your body must have enough of these vitamins to survive. Fat soluble means that there must be fat present in order for the vitamin to be metabolized, and the vitamin will “hang around” in your system and can accumulate. Technically you can O.D. on the fat soluble vitamins when taken in supplement form…more on that later…
Being a cancer survivor, I was particularly interested in the role of cancer prevention. It was discovered that Vitamin D plays an important role in the management of “cell elimination” or apoptosis. When cells don’t belong, there is a mechanism in the body that arranges to have them stop reproducing. This happens, for example with fetuses and with children, who are growing and changing. Their bodies morph because some cells grow, and some get rearranged and disappear. An average tween (ages 8 – 14) losses approx 25 billion (with a “b”) cells every day to apoptosis. If this “cell subtraction”, if you will, goes unchecked, abnormal overgrowth of cells can occur, which is another term for cancer.
Early studies also show that Vitamin D can actually destroy cancer cells and prevent spreading.
Recently, over the past 2 years or so, the Vitamin D levels of breast cancer patients were checked. It was found that a significant number of breast cancer patients, for whatever reason, had very low levels of Vitamin D. It was suggested that increasing women’s Vitamin D level to “adequate” (35-74 ng/ml in the blood measured as calcifediol or Vitamin D 25-hydroxy) could save 65,000 women from developing breast cancer every year. A study of over 1400 women in the general population showed that over 50% of them had inadequate Vitamin D levels.
When my doctor checked my Vitamin D level 2 years ago it was in the neighborhood of 20 ng/dl! Too bad this was after I had already been diagnosed with Stage III breast cancer 3 years earlier. I was prescribed high dose Vitamin D for 6 weeks and then was told to “take extra Vitamin D” every day. Now my vitamin D is check routinely to make sure it is within the desirable range. I like to keep mine as close to 70 as possible without going over….(reminds me of The Price is Right…)
There is considerable scientific evidence that 1,25-dihydroxy vitamin D (the metabolized form of vitamin D in the blood) has a variety of effects on immune system function as well, which may enhance general immunity.
How do I get enough vitamin D?
Vitamin D comes in 2 forms: Vitamin D2 or Vitamin D3. Vitamin D3 is animal based made from skins or sheeps wool. Vitamin D2 is plant-based for those of you following a strict plant-based diet.
Naturally: Our skin will produce vitamin D by exposing it to sunlight without sunscreen. 5 – 10 minutes a day 3 x week is sufficient to get adequate doses of vitamin D in your system. However, the solar index (a rating system of how strong the sun is) must be a certain level and you must exposed your arms and legs to get sufficient D production. This small amount of sun is not enough to put you at any increased risk of skin cancer, but the Skin Cancer Foundation still warns of excess exposure.
Foods: It is hard to eat enough foods to get the levels of D you need. Foods contain, or are fortified with the form D2 or D3. You will find D in mushrooms, eggs, fish and fish oil, fortified dairy products and (dare I say it?) beef liver (ugh) and cheese. Difficult for those on vegan or low fat diets, but with almond and rice milk producers adding D, it’s becoming easier. Amazingly, you can create little “vitamin D factories” out of mushrooms by simply exposing them to 2 days of sunlight!
Supplements: Here is where it gets tricky…..initially, the RDA (recommended daily allowance) of vitamin D was thought to be 200 UI/day but we now know that this amount just is not enough. The consensus is that every adult should be taking 2000 IU/day. especially, the elderly, dark skinned people, those who live in colder climates (don’t get sunlight exposure), over weight (vitamin D is prevented from absorption in overweight persons) and those who have inflammatory bowel disease like Crohn’s The paradox is that we each metabolize the vitamin D at different absorption rates. So while I might take 2000 IU of Vitamin D, and you take the same, I will actually absorb 1500 IU and you will absorb 1000. It all depends on our gut and how healthy that is because that’s how the D gets in your blood. (Which is why it’s so important to get your levels checked)
Toxicity: Initially, there was not enough evidence to put a number on the upper limit for intake of vitamin D. Early studies showed that abnormally high levels of blood calcium were observed in those that took in excess of 50,000 IU /day of vitamin D. This led the Food and Nutrition Board to establish VERY conservative maximum upper intake levels of 2000 IU/day but this level is not based on anything but conjecture and it means nothing without knowing what the blood levels are. Generally blood levels under 90 ng/ml have no adverse effects.
There is now exccellent research that indicates that Vitamin K2 (not the Vitamin K1 that everyone is familiar with and has to do with helping your blood to clot) plays a vital role in the metabolism and function of Vitamin D. Entire books have been written on the subject. The most comprehensive one is written by a naturopath (DoctorKateND.com). Taking Vitamin K2 actually protects you from the effects of too much Vitamin D. I plan to write a full blog post on the summary of this book as Vitamin K2 also has a lot to do with cancer risk as well as osteoporosis.
Since 1997, more and more studies have been done that show vitamin D toxicity is very unlikely in healthy people at intake levels lower than 10,000 IU/day. (I have friends with a history of breast cancer and they see naturopathic doctors who prescribe taking 10,000 iu/daily) but again, the key is knowing your blood level.
Toxicity can further be avoided by taking it in conjunction with Vitamin K. When taken with Vitamin K, vitamin D is less likely to reach toxic levels. Certain companies are now making Vitamin D with Vitamin K together. The RDA for Vitamin K is 150 mcg/day. Not much info on this, but I’m told the data is there, and there will be more supplements that contain a combo of vitamin D and K in the future. In the meantime, you might want to take your supplement with your dark green leafy salad (the darker the leaf, the more Vitamin K…parsley and fresh basil count too!)
Vitamins are not regulated by the FDA and because of that there is no guarantee that because the bottle says “vitamin D3 1000 IU”, that it contains what it states.
Pick a vitamin company that you trust. Look at their philosophy….look at who owns the company…. how long have they been around….any claims about certain products should have data to support it. Call the company and ask questions.
Vitamins lose their potency so check expiration dates.
Look for a descriptive label…..just “Vitamin D”…..or Vitmain D3?
Look at the fillers….yeasts, preservatives….bulking agents, binding agents, etc….
Do they “do good” for the community? do they donate a portion to research etc?
What I do:
I would strongly suggest, especially women, ask you doctor to check your vitamin D level (ask for the vitamin D 25-hyroxy blood test) , and treat accordingly.
I take 4000 IU/day because…..I checked my levels after taking the prescription doses for 6 weeks. My level was only 45 ng/ml (which was fine by my doctor, but not for me) I increased my daily intake to 4000 iu/day and checked it after 6 months. It went to 60 ng/ml. I take my D3 with my calcium (that has Vit K in it)
JUNE 2013 update: I have a theory that healthy guts need less D and by a study of one (me) I have proven it. When I wrote this article I was following a “healthy” diet…no red meat, no processed foods, little dairy. Since then, I have become strictly plant-based…no meat, dairy, no yeast, no processed foods, nothing artificial. I eat whole, clean, plant-based foods and very little wheat. My Vitamin D blood levels have steadily risen with taking 4000 IU/daily and now I am maintaining a Vitamin D blood level of 67 while taking only 2000 IU/daily.(two years ago I needed twice that amount to get the same levels) My theory is that an improved diet and bowel health will lead to more efficient absorption. You can get more info on a plant-based diet here. Again, this is my “study of one 🙂
March 2014 update: As I wrote in my book, Vitamin K is imperative to include if you want your vitamin D levels and Calcium levels to remain healthy. I just attended an Annie Appleseed Conference where I heard a lot about Vitamin K. I am currently reading the book “Vitamin K2 and the calcium paradox” as suggested by the speaker. I have also ordered Vitamin K2 (MK4) for inclusion in my daily regimen. I was having some symptoms of palpitations when my serum Vitamin D level was reaching 70, but I’m told with adding Vitamin K, that won’t happen. I’ll report back…
I welcome any comments, questions as this is a sharing forum.
New study update March 20, 2012: Scientists pinpoint how Vitamin D helps clear plaques in the brain found in Alzheimer”s
Please see these sites for additional information:
Thanks for reading!