Thursday, January 3, 2013

Vitamin D -"The Sunshine Vitamin"

Vitamin D is important for bone health and for preventing cancers -especially breast and prostate cancer. Vitamin D helps maintain healthy levels of calcium in the blood. It increases calcium absorption in the small intestine and decreases calcium excretion in the urine. A deficiency of vitamin D can can cause increased demineralization of bone, leading to weak and soft bones.

Low levels of vitamin D have also been associated with weight gain and increased risk for dementia and Parkinson's disease.

What is the status of most Americans? Most Americans are below the optimal vitamin D levels of 35-50ng/ml, and half are below 20ng/ml which may be dangerously low.

What is the RDI for vitamin D? It is 400IU/day. However, most persons taking only this amount of vitamin D (which is the amount in most multivitamins) will be deficient in vitamin D. For most people to achieve adequate levels of vitamin D they need to take between 1500-2500IU of vitamin D per day. (I usually take a multivitamin + 2000 IUdaily).

How do you know how much you should take? You need to get your levels checked. Dr Joel Fuhrman (Eat to Live) states that he believes this test is as important as checking your cholesterol. Before I took extra vitamin D (in addition to my multivitamin) my levels of vitamin D were low in the winter especially.

Which brings up another question. Can't I get enough vitamin D from sunshine. If you live in northern latitudes the sun is not at a sufficient angle between mid-September to mid-March to get enough vitamin D produced from your skin. Also sun blocks decrease vitamin D production from the skin and also persons with dark skin tend to not make as much vitamin D from sun exposure. If you spend most of your working hours indoors you may not even get enough vitamin D in the summer months.

What are some of the risks of deficiency? One study showed a 75% increased risk for all-cause mortality (death) in those whose intake was in the lowest quartile. Another study showed a 50% decrease risk of breast cancer in just 4 years in those who had adequate levels from supplementation.

This brings up another question-can I take too much vitamin D? In the study on breast cancer the lowest risk was found in the persons whose levels were between 35-50ng/ml and as levels went above 50 then cancer risk also increased again.

Dr. Joel Fuhrman had an interesting patient who was having repetitive vomiting for 3 years (and was eating a healthy vegetarian diet). He had been to 3 separate GI specialists who had each recommended different types of treatment. He then came to see Dr Fuhrman and he checked the patient's vitamin D level and it was only 7ng/ml. He started supplementation and all his vomiting went away in just a few weeks.

So the bottom line is get your vitamin D level checked. If you are low then consider supplementing with 1500-2500IU/day and then check your levels again to make sure they are in the optimal range.

Dr. Jerry Fessler