Posts Tagged ‘25-hydroxy Vitamin D’
Today I ran across mention of an old observational study of seasonal colds and flu in northern (temperate zone) and southern (tropics) India. Colds and flu had no seasonality in southern India where vitamin D from sunshine is equally available all year.
Colds and flu were seasonal in northern India closely following the months when vitamin D is not readily available from the sun which is too low on the horizon to produce vitamin D. There is not direct evidence that lower vitamin D levels allow more colds and flu, but it seems reasonable.
We have long known that vitamin D is involved in human immune system function as well as bone health. e.g. A National Institute of Health study found that persons with monohydroxy-vitamin D levels over 33ng/ml have half the risk of colorectal cancer as those with less than 12 ng/ml.
Vitamin D toxicity is possible but very rare according to the Mayo Clinic, requiring doses of 50,000 IU (1250 mcg) daily for months.
My experience in Iowa is that most persons not taking at least 1000-2000 IU (25-50 mcg) daily have vitamin D levels below 20ng/ml December through April. That is also cold and flu season.
I take 5000 IU (125 mcg) daily to keep my level at 50-60 ng/ml. That can’t hurt and it might help prevent viral infections. Over age 65, I have started working from home and am setting up TeleMedicine capabilities because of COVID-19 guidelines.
Follow your state’s health department guidelines. And extra vitamin D could help. If you have not taken any in the past, up to 5000 IU (125 mcg) daily should be safe until you have a chance to check your level.
Jay Ginther, MD
So how do you find out what aspects of your bone health are pretty good already, what will be easy to fix, and what will take some real work? Start with a Complete Bone Health Evaluation.
DXA is about 1/3 of the story and should include both hips and spine. When you are as old as I am, the spine probably is too arthritic to be really accurate, but helps complete the picture. If you have had a total hip replacement, you should use the non-dominant forearm.
VFA will pick up many persons at increased fracture risk who are missed by DXA alone. You should ask for VFA, especially if you or a parent have kyphosis (humpback) or have lost height.
The FRAX calculation picks up different individuals at high fracture risk.
Blood tests should include CBC, CMP, TSH, PTH, and 25-hydroxy Vitamin D as a start. Further testing may be needed.
A medical history and examination focused on bone issues is a critical part of the full consultation. We allot a minimum of 30 minutes for discussion. Often a follow-up visit is needed to be sure both we and our patients are clear on the whole picture.
DXA alone misses over half of the individuals who need to improve their bone health. Get a Complete Bone Health Evaluation.
Jay Ginther, MD
Spring! The Sun is back for more than 12 hours daily! The sun crossed the equator at 0529 CDT. Vitamin D? Not so fast. This is Iowa and we are still too far north.
Your skin can make Vitamin D when exposed to strong enough sunlight. Strong enough sunlight happens when the sun is high enough in the sky that its UV rays are not blocked by the atmosphere. This happens at mid-day all year round in the tropics.
Iowa needs to wait another couple of weeks for our first moments of Vitamin D from the sun. Mid-day is around 1:10 to 1:25 pm CDT, depending on location. Southern Iowa will get enough sunlight several days before northern Iowa. Late June we will have 4-5 hours of opportunity.
Unfortunately, Vitamin D, Sunburn and Skin Cancer are often a package deal. You can encourage them all, or block them all with Sun-block.
Your safest move is to protect yourself from sunburn and skin cancer, and take your vitamin D3 tablets or gel-caps. A 25-hydroxy Vitamin D blood test will show if you have achieved the ideal range of 40-80 ng/ml.
You need to take control, but this is one area where naturally can have a significant downside.
Jay Ginther, MD
Vitamin D is necessary in order to absorb Calcium from your diet. Your skin can make some Vitamin D from the Mid-day Sun, but only in the “summer”. The sun is high enough above the horizon at mid-day only 5 months of the year in Iowa. Over half of Iowans are low on Vitamin D as summer ends in September. 7 out of 8 Iowans are low by mid April when we can first get a few minutes a day of Vitamin D. That’s the Good News.
The Bad News is that Sun Block blocks Vitamin D production in skin. You need to risk Sunburn and Skin Cancer “naturally” if you want to make your Vitamin D “naturally”. Plus you need to expose enough skin (determined by your age and personal genetics) to make enough Vitamin D.
Foods naturally high in Vitamin D3 include “yummy” Seal Blubber and Cod Liver Oil. Most Fish Oil does not have much D3. Vitamin D2 from plants (like mushrooms) is much less long lasting than D3, so we are talking pounds of mushrooms daily.
Your easiest and safest move is to take extra Vitamin D3. The amount of D3 in your multiple vitamins and minerals, calcium supplements, and milk combined are very rarely enough. Most of us need 2,000 to 5000 units of additional D3 daily.
Test for 25-hydroxy Vitamin D Level to tell if you are taking enough to get between 40 and 80 ng/ml in your blood.
Help to Take Control Naturally by getting enough Vitamin D.
Jay Ginther, MD