Day 105: Vitamin D

Well, I'm sitting on my bum and trying to stay off the legs in prep for the Sydney Half Marathon tomorrow. This week has been a balancing act of trying to get back in shape on the bike but not getting too sore for the race/run tomorrow. I will try to remain realistic so as not to blow up. I had great running sessions on the Goldie about 2 weeks ago but my trip to New Zealand stalled the training a bit. I have lots of miles on these legs but not very much speedwork so I'm thinking anything between a 1:20-1:22 will be nice. Either way, it will be fun to do a new race in a new city. Since I'm on me bum, thought I would finally do the posting on Vitamin D.

Vitamin D is the new vitamin E. Doctors have long known that Vitamin D helps in the absorption of calcium to make bones dense and strong. More recent research touts of its ability to help prevent several cancers, cardiovascular disease, autoimmune disorders, psoriasis, diabetes, depression, and respiratory infections including colds and flu. There is very compelling evidence that increasing Vitamin D levels in the body can significantly decrease the occurrence of breast cancer. On my recent trip to New Zealand, I discussed Vitamin D with my friend Maggie, who is a physician. She agrees with the benefits of Vitamin D and like most doctors, believe that most of the general population is deficient in Vitamin D. I'm a bullet point type of guy, so here is what you need to know about Vitamin D:

• Most of the body's Vitamin D production is activated by sunlight. However, people nowadays spend a majority of their time indoors; and if outdoors, they put on sunblock which blocks Vitamin D production in the skin.

• Darker skinned people and aging skin make less Vitamin D than those with lighter skin and younger skin respectively.

• Ask your doctor to check your blood levels of 25-Hydroxy (25-OH ) vitamin D (Vitamin D3). The normal range is 30.0-74.0 nanograms per mililiter (ng/mL) of blood, or 70-120 nmol/L.

• If you decide to take a Vitamin D supplement, make sure it is the biologically active (greater absorption) Vitamin D3 (cholecalciferol) and not Vitamin D2. Some doctors are recommending that you supplement with 2000 IU of Vitamin D3 per day. Vitamin D is a fat-soluble vitamin and it can be toxic if too much is taken. To give you an idea of numbers, your body can produce between 10,000-20,000 IU per hour under optimum sunlight conditions. Also, research shows no adverse effects with Vitamin D supplementation up to 10,000 IU daily. Always take your Vitamin D with a fat-containing meal to ensure absorption.

• Vitamin D rich foods include fortified milk and cereals, eggs, cod liver oil, tuna and cold water fish such as wild salmon, wild cod and sardines. However, it is difficult to regularly eat enough of these foods to build up your Vitamin D stores. The best way to produce vitamin D is sunlight exposure; the ultraviolet rays trigger Vitamin D synthesis in the skin.

• Get some sun exposure on your skin without sunscreen for 20-30 minutes in the morning or late afternoon. Do use sunscreen during the midday to protect your skin.

• Be sure to get retested to monitor your Vitamin D levels.

I want to qualify the Vitamin D info by saying that 15 years ago or so, many experts were touting Vitamin E similar to Vitamin D. Now, it is well-regarded that too much Vitamin E is harmful. My best advice is that if you decide to supplement with Vitamin D, consult your physician to make sure you are taking the right dose for you.