Science is discovering new benefits of our sunshine vitamin (D) every time we turn around.

This sounds so crazy, but it’s true. I remember as a young girl, if I got a sore throat, my grandmother would have me go outside and face the California sun with an open mouth. It sounds more than a little like quackery (of course, my grandmother wasn’t a doctor, so maybe not quackery). She was born before the turn of the century; no, not 2000, of course, 1900; so I cut her a little slack. But, believe it or not, now there’s evidence that “When a T cell (cells that are part of your immune system) is exposed to a foreign pathogen, it extends a signaling device or ‘antenna’ known as a vitamin D receptor, with which it searches for vitamin D,” explained Carsten Geisler of Copenhagen University. Why does Dr. Geisler find that so interesting. It means that without enough vitamin D the immunity action of the T cells can’t even mobilize to do their job. Read more in Nature. It seems likely that, I would not have needed to open my mouth, but just get the sun on my skin.

I feel compelled to begin my discussion of vitamin D by saying that vitamin D is not, strictly speaking, a vitamin. Vitamin D is a hormone (made in one place in the body, to be used in some other place in the body.) Because the body makes vitamin D, if an individual has an adequate exposure to sunlight they wouldn’t need to ingest vitamin D. Vitamin D is manufactured by our bodies, from sun exposure. Unfortunately, above the latitude of 42 degrees north (a line between the Oregon/California border and Boston) the sunlight is insufficient to make vitamin D from November through February (four months); the farther north beyond 42 degrees a similar line is, that reduced intensity of the sun will last for up to 6 months. Below a line (34 degrees north) between Columbia, South Carolina and Los Angeles, we should receive enough sunshine to make active vitamin D. Unfortunately, there are many other factors that influence our ability to produce adequate vitamin D; like pollution; glass windows; homebound individuals; sunscreens and clothing covering most of the body (like long robes and head coverings); people with dark skin; those that have trouble with fat metabolism (fat is necessary to absorb vitamin D); those who have had gastric bypass surgery(those with bypass can’t absorb it in the upper small intestine where vitamin D is absorbed); or who are obese (much of the vitamin D that is made in the skin gets ‘trapped’ in the fat. Steroids and other medications that inhibit fat metabolism are also a factor in having sufficient vitamin D.

In addition to difficulty getting enough UV light there is a number of other issues that can impact insufficiency of vitamin D.  They include: breastfed infants, especially African American infants); older adults (decrease in the ability of the skin to synthesize vitamin D and the kidneys’ ability to convert to the active form of vitamin D.

In biochemistry you must learn about how the various forms of vitamin D are formed, what makes them active, and what the different forms can do. I realize that this is a fairly vague explanation, but I don’t want to try to cover a whole section of biochemistry right here in this blog. If you want to learn more you can go to Wikipedia or Colorado State’s diagrams and explanation.

Years ago when vitamin D was mentioned it was almost always in conjunction with bone strength and calcium metabolism. The main job of vitamin D that was taught was the job of absorbing calcium and its involvement in mineralizing bone.

A deficiency of vitamin D causes or makes worse a number of problems including: rickets (the failure of bone to properly mineralize); osteopenia (the thinning of the bone – the leaching out of the minerals that make bone heavy and strong); osteoporosis (the bones are so weak, that they break very easily, the vertebrae crush and it can cause a dowager’s hump – person is stooped over and often in pain); muscle weakness; fractures; some common cancers (including colorectal cancer); autoimmune diseases; kidney disease; high blood pressure; infectious diseases and cardiovascular diseases. And maybe even type-1 diabetes.

It’s is actually very exciting to me that science is learning how vast the participation of vitamin D is in the body. One of the recent findings reported in Nature is that vitamin D is necessary to trigger T cells (part of the immune system) to be active against disease. There are a number of studies that are finding associations between vitamin D and cardiovascular health. A study at the Jikei University School of Medicine in Japan has been published in the Journal of Clinical Nutrition; has found a significant reduction of flu and asthma attacks in school children who were supplemented with vitamin D. It was especially successful in the children whose blood levels of vitamin D were low at the start of the study. One study done at Harvard was published in the Archives of Internal Medicine. It found that low levels of vitamin D might be associated with increased risk of heart attack. There have been other benefits linking vitamin D and peripheral arteries (the arteries that carry blood to the head, arms and feet); one is reported in Arteriosclerosis, Thrombosis, and Vascular Biology. Research at Johns Hopkins University was led by Richard Semba; one of the pioneers in discovering several biologic mechanisms that help explain how vitamin D is linked to several effects, including the regulation of immune health, blood pressure and the reduction of arterial hardening. Clinical Endocrinology and Metabolism reported findings that insufficient vitamin D is associated with the accumulation of fat in muscles, which leads to lower muscle strength.

Supplements

The U. S. Office of Dietary Supplements publishes information about the supplementation of vitamin D. Very few foods contain vitamins D; some that do:

The flesh of fish (such as salmon, tuna, and mackerel) and fish liver oils are among the best sources. Small amounts of vitamin D are found in beef liver, cheese, and egg yolks. Some mushrooms provide vitamin D in variable amounts. One new discovery has led to the availability of a new product; mushrooms with enhanced levels of vitamin D from being exposed to ultraviolet light under controlled conditions. But, by far, fortified foods provide most of the vitamin D in the American diet.

Because of past lessons learned when taking supplements went really wrong, some of the Public Health researchers want to be very cautious before we all jump on a ‘band wagon’ and take supplements of vitamin D. Some of the issues involved are reported in an article in the Annals of Internal Medicine, March 2, 2010.

There have been many promising studies, but quite a bit of uncertainty about the optimal dose of vitamin D to take, if a person is deficient. Some of our northern European ancestors routinely took cod liver oil – I remember it, myself, as a child. Disgusting taste!

It’s a serious issue, as we already know that vitamin D, being fat-soluble can become toxic, if given at too high a dose. It accumulates in the body and is not eliminated in the urine like water-soluble nutrients.

Fortunately, you do not get vitamin D toxicity from excessive exposure to sunlight. But you must be mindful of the risk of skin damage from too much sun exposure. Vitamin D toxicity is always the result of overdosing on vitamin D supplements.

Hope for the future - Dr. J. Brent Muhlestein, director of Cardiovascular Research at Intermountain Medical Center Heart Institute in Salt Lake City, gave a report to the American College of Cardiology in Atlanta.  He explained that new “studies that show a relationship between heart attack and vitamin D are going to provoke a lot more research to understand what is going on.”

Meanwhile, you may want to consider having your doctor test the vitamin D level of your blood. If it’s too low, your doctor will prescribe either an over-the-counter tablet or a high intensity prescription. Be sure that you have a re-check, if the doctor prescribes a high intensity prescription – you don’t want to go into vitamin D toxicity. With all this complexity and risk, I would nostalgically like to just open my mouth and tip my head up to the sun.

Green Beans with Lemony Leeks

Green beans were often served for Easter meal in my ‘growing up’ home. The beans almost always were generously cooked with ham or bacon, added butter and quite a bit of added salt. An interesting thing about this recipe is that, the saturated fat (butter, ham, bacon), and most of the salt is not missed. Dr. Grandpa and I enjoyed this green bean recipe more than the ‘old way.’ It’s so wonderful when something that is good for you, tastes so good. This is one of those recipes. You can learn a little ‘trick’ from this recipe; use a little lemon or lime, to cut the salt of other recipes.

Ingredients:

¼ cup extra virgin olive oil, separated

2 cups thinly sliced leeks (about two large leeks)

2 pounds of thin green beans

5 teaspoons lemon zest

½ teaspoon salt

½ teaspoon black pepper

Directions:

Heat 3 tablespoons of oil in a skillet. Carefully add the leek slices, so as not to splatter yourself. Sauté the leeks until lightly browned and crisp, about 6 – 7 minutes.

Cook the green beans in salted boiling water (most of this salt is poured off with the water), until tender-crisp; about 8 minutes, depending upon the size and temperature of the beans. Drain the beans.

Heat one tablespoon of oil. Add and mix the lemon zest, salt and black pepper; infuse the lemon flavor in the oil for a minute, while stirring. Add the leeks, and green beans to skillet. Sauté for a minute or two, until the ingredients are mixed; serve and enjoy.

Start with two healthy leeks.

Slice the leeks and zest the lemons.

Saute the leeks.

Keep sauteing until crispy and browned.

Remove toasted leeks to a plate.

Boil the green beans.

Put the salt, pepper and lemon zest with the oil to infuse the flavors.

Add the beans and leeks and saute for a minute or two.

Serve and enjoy.