Dr. Kevin Most: Vitamin D
Vitamin D, Why would we talk about Vitamin D in the summer. Isn’t this usually a winter discussion??
We have talked about Vitamins and supplements in the past, the need for Vitamin D supplements in the winter is very important and we have highlighted it in the past. Recently a study came out on the benefits of Vitamin D, as well as the need for Vitamin D in our daily lives. I thought we would take a minute to discuss Vitamin D and its importance in our health. For all of you purist out there, it is true that Vitamin D is technically not a Vitamin. This is good trivia question or cocktail party discussion. A Vitamin by definition is an organic compound that is essential for normal growth and needed in our diet because they cannot be synthesized by the body. Well, Vitamin D is actually a hormone that is produced by the kidney that is activated in the skin with exposure to sunlight, so in the true definition of the word, Vitamin D is actually not a Vitamin. Many feel it was lumped into the Vitamin world as its importance in the treatment of Rickets had to be elevated to gain attention.
We know that Vitamin D when taken with calcium supplements helps with the body to absorb Calcium. This is important with men and women trying to maintain bone strength to prevent osteoporosis. Preventing osteoporosis helps us prevent hip fractures and really all bone fractures.
During the summer we probably don’t think much about needing a Vitamin D supplement. We get enough sunlight exposure that we make enough Vitamin D don’t we?? Well for those of you who listen and wear sunblock on a regular basis , you may still need Vitamin D supplement. Sunscreen can actually block up to 98% of the natural sunlight needed for production of Vitamin D in your body. So if you are really good about wearing sunblock a little supplement of Vitamin D may be in order this summer. We all know that in the winter with many indoor activities and the shortened day light a supplement of Vitamin D is needed for all of us. We also are seeing more individuals staying out of the sun as much as they can as they fear skin cancer
Even with this knowledge, estimates are that over 40% of those in the US, are deficient in Vitamin D. You may find this very surprising, but in fact early in the 1930’s the rates were much higher. The deficiency was so great that we had many children with the disease Rickets. This led to weakened bones and poor immune systems. However you will see that now more foods are fortified with vitamin D, they include milk, orange juice and many breakfast cereals. This fortification started in the 1930’s as a way to prevent rickets in children. Note the focus on dietary items for children as bone development is key to these young individuals.
So why did we have to add Vitamin D to those products?
The recommended intake of Vitamin D for adults is 400 – 800 IU, however many are now looking at changing that to 1,000- 4,000 IU daily based on some new research. We know toxicity from Vitamin D is usually not impacted until individuals take supplements well above 10,000 IU daily for weeks. Many may want to take Vitamin D via their diet, instead of in a capsule. Now we know there are some foods with Vitamin D that could give a diet source, however very few foods contain Vitamin D and the amount needed would be difficult to achieve just thru diet and sun exposure or vitamin supplements are probably needed. That being said, lets at least list a few of the common foods where Vitamin D is found and how much is in the amount.
Salmon 3 ounces – 450 IU’s
Milk 1 cup – 110 IU’s
Orange Juice (fortified with Vit D) 130 IU’s
One Egg 40 IU’s
Swiss Cheese 1 slice – 6 IU’s
Now for Dave and all you Kale fans out there you will be sadden to hear that Kale does not contain any Vitamin D. However , Kale does have Vitamin K, which is important also in maintain bone strength.
So you see getting the 800 IU daily recommendation is difficult from just diet sources. However you will see that more foods are fortified with vitamin D, they include milk, orange juice and many breakfast cereals.
So who are we concerned about when we think of not getting enough Vitamin D, well interestingly it hits the 2 extremes in age. Babies who are exclusively breastfed. Breast milk does not have the needed Vitamin D concentration present and thus supplemental Vitamin D is recommended for those individuals. We do not want these infants to get their Vitamin D from sun exposure as we try to limit sun exposure in this age group. We also see that as we age our ability to make Vitamin D decreases. Seniors have skin that even when exposed to sunlight may not make enough Vitamin D, they also spend more time indoors. This lack of Vitamin D as we age may be one of the major causes of hip fractures in this country. We are also concerned about those who live in the northern parts of the world, were direct sunlight is not available in enough concentrations for many times of the year. This is also why supplementation in the winter is important as we often go to work in the dark and come home in the dark and have little or no sunlight exposure in the winter.
We are also concerned about Vitamin D deficiency in patients with inflammatory bowel problems as well as those who have had gastric bypass as both of these conditions may limit the amount of Vitamin D that is absorbed thru diet.
We also have concerns with individuals who ingest too much vitamin D as toxicity, but over dosing on supplements can experience toxicity. Now excess sunlight cannot lead to Vitamin D toxicity, so it really comes down to ingestion of excess supplements. Excess intake can cause nausea, vomiting , weakness and diarrhea. Now as I said earlier a large portion of the country is deficient in Vitamin D. It is only a problem when we have individuals taking high dose supplements, like over 30,000 IU a day. Personally I take 600 IU in the winter and 300 IU in the summer. A new study may have me increase that to 1200 IU in the winter and 600 IU in the summer
So why are doctors so concerned about Vitamin D levels?
What health benefits do we get from Vitamin D? You may be surprised. Many of you will immediately say bone and tooth strength, that is well known and very true. We know we need vitamin D to help us absorb calcium as well as maintain bone strength.
Would it surprise you that studies have shown that Vitamin D status impacts our cancer risk? New data published a few weeks ago shows that Vitamin D may be protective against Colon cancer. This study joins the many other health benefits we know about Vitamin D. This recent study may change how we view Vitamin D levels in the blood. Currently we take “normal” as the level of Vitamin D in the blood needed to maintain bone growth and strength. This study however showed that levels above the what is considered normal, had a 22% lower risk of developing Colon Cancer, and those with below normal Vitamin D levels had a 30% higher chance of colon cancer. This study has shown that perhaps we need to move the normal range of this test higher in order to receive the protection from Colon Cancer. It may also lead us to change the daily intake that is currently recommended.
Studies have also shown that Vitamin D has health benefits when we look at our immune system, heart disease, depression and even Multiple Sclerosis. Vitamin D has been found to have a large impact on each of these diseases. When you put it all together we realize that Vitamin D does a lot more to our health than giving us strong bones.
So the bottom line is that Vitamin D is important to your health in many areas, and having a discussion with your doctor about supplementation may be a good idea.