Out with Vit C - In with Vit D!

A new study published in Archives of Internal Medicine reports that "higher levels of vitamin D may protect against the common flu and cold".

This study found that among 19,000 adults and adolescents, people who had the lowest blood levels of vitamin D were 40% more likely to have recently experienced a cold or flu. The authors of this study also noted that low levels of vitamin D were linked to even higher risk of respiratory complications in those who suffer from chronic respiratory disorders (asthma, emphysema, and chronic obstructive pulmonary disease).

http://archinte.ama-assn.org/cgi/content/abstract/169/4/384

Although further studies are needed to confirm this observation, it certainly contributes to the list of potential health benefits linked to this immune fighting vitamin!

Note to my friend with pneumonia: Another reason to take those vitamin D pills !!

Vitamin D: Recommendations for Children

In 2008, the American Academy of Pediatrics (AAP) recommended that vitamin D be increased from 200 IU to 400 IU per day for children. Vitamin D is required for calcium absorption and promoting bone mineralization. Vitamin D deficiency in children can cause rickets, a disease that affects the developing bones of children. According to the AAP, children 1 year of age and older should consume vitamin D from vitamin D-fortified milk and other fortified foods and take a supplement if needed, under guidance by a pediatrician.

Milk is one of the most important sources of vitamin D (and calcium) in pre- and school aged- children. If your child consumes three 8-ounce glasses of low-fat vitamin D-fortified milk a day, they will get 75% of their daily value (DV) for vitamin D. However as many parents know, it is difficult to get a child to consume one glass of milk, let alone three!

A couple of years ago my son stopped drinking milk (once I took away his sippy cup) and I was faced with the reality that I was a parent (with degrees in nutrition) whose son did not drink milk ! I hadn't expected this dilemma because my son loved his milk (but obviously it was the sippy cup he loved more). So I broke my first preconceived nutrition notion which was "no chocolate milk allowed" and proceeded to give him low-fat chocolate flavored milk a couple of times a week. It contains more calories and twice the amount of sugar as white low-fat milk (even now the makes me cringe!) but it also contains the same amount of vitamin D. The way I view this is as follows: imagine your child is learning to drive, you let them practice in your new car but you purchase an old car for them, different vehicle but it gets them from point A to point B. Thats how I see chocolate milk - as a different vehicle, not ideal, but hopefully they'll upgrade soon !! I kept offering my son white milk and eventually he did try it again and I soon weaned him off the chocolate milk (once its not in the fridge the battle stops!). As a nutritionist I encourage you to give your children low fat white milk, but as a parent I know sometimes this is an impossible battle, and we have to approach the battle field from a different angle!

With respect to supplements, I think giving your child a multivitamin supplement that contains 200 IU of vitamin D, particularly in the winter months, is a good idea. My advice is aim to get at least half your childs vitamin D requirements (i.e. 200 IU) from dietary sources - milk, fortified orange juice, breakfast cereals and fish, and the other half from supplements. Alternatively, try your ancestors remedy - a teaspoon of cod liver oil ! This contains 400 IU of vitamin D. Perhaps the new flavors of cod liver oil disguise the taste - let me know how you get on with that one!

Question Everything

After reading my blog on vitamin D, I was asked some excellent questions.

One friend asked "Just tell me how I can get 1,000 IU a day from my diet ? This question was followed by, oh and by the way, I am NOT getting my blood taken!"

"Its really difficult to get 1,000 IU from diet alone. Most brands of multivitamins contain 400 IU and so I recommend you take a multivitamin. With respect to food sources, the richest source of vitamin D comes from fish. For example, a portion of cooked salmon (3.5 ounces) contains 360 IU, canned tuna in oil (200 IU), or cooked shrimp (140 IU). Other sources include dairy products, such as a cup of milk (100 IU) or a yogurt (80 IU) . You can also get vitamin D from orange juice that is fortified with calcium + vitamin D (100 IU), or from Viactiv calcium soft hews (1 chew = 100 IU), or fortified breakfast cereals (40 IU). And with respect to the blood sample, keep traveling to sunny places and you should be fine ! No need for a blood sample my brave friend"

Another question raised was "Hold on, the label on my multivitamin says I am getting 100% of my daily value (DV) for vitamin D, so this is good, right ?".

"Ok, I can see your confusion. The recommended adequate Intake (AI) for vitamin D is 400 IU. This is the level stated in the Dietary Reference Intakes (DRIs) and is the level assumed to ensure nutritional adequacy. Most dietary supplements contain 400 IU of vitamin D and so it states 100% vitamin D in one supplement. However, most experts believe this is set way too low and the recommendation (by experts in the field) therefore is to increase your intake to 1,000 IU/day"

Another friend asked "You mention that there are two forms of vitamin D, do both forms, D2 and D3, naturally occur in foods ?".

"This is a good question and let me clarify this for you. The vitamin D found in most foods, and in some dietary supplements, is in the form of D3 (but you should check the supplement label). D3 is usually derived from animal sources. Fortified soy milks (e.g. Silk Soymilk) and other soy based drinks contain the less active form of vitamin D, D2. Vitamin D2 is usually derived from yeast."

To my friend who loves ice cream - "sorry to tell you this but ice cream is not a source of vitamin D!"

Please keep asking questions, you can e-mail me at beyondnutrients@gmail.com

Don't Doubt Vitamin D !

Experts in the field are convinced we are not getting enough vitamin D and the evidence is pretty convincing. There is a growing list of health conditions and diseases that vitamin D deficiency/ insufficiency* has been linked to, such as

Osteoporosis
Type 2 Diabetes Mellitus
Cardiovascular Disease
Muscle weakness
Fractures
Cancers
Autoimmune diseases
Dementia
Hypertension

To mention just a few...

*criteria for deficiency is a serum 25(OH)D [25 hydroxyvitamin D] less than 50 nmol/L, and vitamin D insufficiency is a serum 25(OH)D between 50 and 80 nmol/L (experts believe this reflects a vitamin D status that is too low to prevent some disease).

Last year I was vitamin D deficient. I suspected that I was deficient for several reasons:

(1) I live on the East Coast.
(2) I lather myself in sunscreen from May to September (tanning is not an option for most Irish).
(3) I don't drink any milk (there is a story behind that one).
(4) Like most, I only consume fish once a week.

A simple request to my Dr. asking that she test my serum 25(OH)D levels confirmed what I had suspected and so now I take a vitamin D supplement.

Nutrition 101:
Upfront, there are two points you need to keep in mind. First of all, there are three ways you can get vitamin D (1) through sunlight exposure, (2) from food, and (3) from supplements. Second, there are 2 forms of vitamin D: D3 (cholecalciferol) and D2 (ergocalciferol). Vitamin D3 is the most potent form of vitamin D. It is more effective at raising serum 25(OH)D than vitamin D2 and, it is more effective at maintaining those levels for a longer time. Most supplements now contain vitamin D3, rather than vitamin D2 (but make sure to check the label).

Sources of vitamin D:
Most people know we get vitamin D from sunlight. If like me however, you use sunscreen, you block the UV rays and therefore prevent the absorption of vitamin D in your body. Also, keep in mind the further from the equator you live, the weaker the UV light (note to Irish friends....even on those sunny days you're at a disadvantage!)

With respect to diet, there are few foods that are naturally rich in vitamin D. These include fatty fish, some fish liver oil, and eggs from hens fed vitamin D. Milk products, breakfast cereals, infant formula, and juice can be good sources if fortified with vitamin D. Contrary to what you may believe, most cheeses and other dairy products are not fortified with vitamin D.

**NOTE: THIS SECTION IS NOT NECESSARY TO READ IF YOU'D RATHER SKIP AND GO STRAIGHT TO THE BOTTOM LINE (SEE BELOW).
Regardless of where vitamin D is obtained (sun exposure, food, and supplements) it is biologically useless! It needs to go through 2 steps in the body to become active. The first step occurs in the liver where vitamin D3 is converted to 25-hydroxyvitamin D [25(OH)D]. As mentioned above 25(OH)D is a blood measure of vitamin D status. The second step occurs primarily in the kidney, where 25(OH)D is converened into the physiologically active form 1,25-dihydroxyvitamin D [1,25(OH)2D]. This is a hormone and it plays many roles in human health. One of the most important roles of vitamin D is in promoting calcium absorption in the gut and maintaining adequate serum calcium and phosphate concentrations to enable normal mineralization of bone.

How much vitamin D should I have in my diet?:
Most experts are recommending 1,000 international units (IU) a day. Check to see how much you are getting from your multivitamin, calcium supplement (most include vitmain D) and then from foods.

(Go to: http://ods.od.nih.gov/factsheets/vitamind.asp#h3).

You should be aware that there is a current recommended tolerable upper intake level (ULs) for vitamin D (i.e. the maximum that is considered safe). This is set at 2,000 IUs a day. Most experts however believe this is set too low and that higher intakes appear to be safe. If you are prone to kidney stones or kidney problems I suggest you seek advice from your doctor. The main reason is that too much vitamin D will cause your body to absorb too much calcium and this can lead to kidney problems.

BOTTOM LINE:
So, here is my advice:

Get your serum 25 (OH) D levels measured at your next physical examination.

Aim to consume 1,000 IU daily (most multivitamins contain 400 IU).

If your serum 25 (OH) D levels are low at your follow up visit, discuss taking a vitamin D supplement.