Working Nights

Here Comes the Sun: Getting Enough Vitamin D When Working Shift Work

The threat of skin cancer looms on the one hand, but the threat of bone fractures, sleep disorders, and depression awaits on the other. What is a shift worker to do? Too much sun causes danger, but many shift workers- shuttling back and forth to work all day, toiling under the gleam of florescent lights, sleeping all afternoon- don’t get enough sunshine in their lives. Vitamin D helps the body use calcium to grow strong bones, as well as preventing rickets and aiding the immune system. While a few foods such as milk and eggs contain Vitamin D, the body mainly produces the vitamin in response to sun exposure, and so the vitamin languishes in dark, night work and shift work environments. It is important for shift workers to understand the workings of Vitamin D and how to get the right amount safely, since these days it’s the rare work schedule that supports a relaxing daily sunbathe.

Vitamin D is an essential nutrient. When Vitamin D works with other nutrients and hormones in the body bone density and health is increased. Most important to maintaining strong bones, Vitamin D controls the levels of calcium in the blood. Vitamin D helps the body absorb magnesium, iron, zinc, as well as calcium.

Yet, Vitamin D has been found to be in short supply in many people. Some studies have found that between 60 and 85% of people are lacking enough Vitamin D. Symptoms of Vitamin D deficiency can include weak bones resulting in fractures, muscle pain, low energy and fatigue, renal or intestinal problems, depression, mood swings and sleep disorders.

Vitamin D is created by the body as a result of exposure to sunlight. The sun radiates energy in a wide range of wavelengths, most of which are invisible to human eyes. Scientists have classified UV radiation into three types – UVA, UVB, and UVC. The stratospheric ozone layer absorbs some but not all of these types of UV:
UVA – Not absorbed by the ozone layer
UVB – Partially absorbed by the ozone layer
UVC – Completely absorbed by the ozone layer

UVA and UVB penetrate the surface of the skin and can cause adverse health effects such as skin cancer, immune suppression, cataracts and premature aging of the skin.

As we have shifted from an agriculturally based society to an industrial one we now experience substantially reduced exposure to sun. Today, most of us work indoors vs. outdoors, drive cars instead of walking and use sun block to prevent sunburn. Employees who regularly work nights have even more difficulty getting enough exposure to natural sunlight. Limiting exposure to sunlight helps reduce the incidence of negative health effects mentioned above, reduced exposure results in lower levels of Vitamin D as well.

Brief exposure to normal UV-B sunlight (10 -15 minutes) several days a week will allow the body adequate time to develop enough Vitamin D. However, the amount of UV-B normal sunlight accessed at any one time depends on exposure time, latitude and altitude of location, cloud cover, air pollution, amount of skin surface exposed, skin pigmentation and season of the year. For example, sunlight exposure from November through February in Boston is not insufficient to produce enough Vitamin D. And complete cloud cover can cut the energy of UV rays in half and shade will reduce it by 60%.

To avoid harmful effects, after the 10-15 minute exposure period, sunscreen with an SPF of at least 15 should be applied. Longer exposure will not increase vitamin D production, but it will increase the danger of skin damage and possibly cause skin cancer; it is important to be careful to not get overexposed.

Vitamin D can also be found in food, especially in eggs, butter, lard or bacon fat and certain fish, such as herring, mackerel, catfish, oysters and sardines. Fish make Vitamin D because of their exposure to algae. However,modern farm raised fish are poor sources of Vitamin D. Eggs contain Vitamin D if the chickens have obtained it from their food or from insects. Meats and fat from pigs and mammals will contain Vitamin D because the animals spend a lot of time in sunlight and eat grass which supplies a precursor to Vitamin D. Milk and juice suppliers also sometimes fortify their products with extra Vitamin D.

Since vitamin D-rich foods are also rich in cholesterol, low-cholesterol diets are inherently deficient in vitamin D. So, Vitamin D can be provided by taking vitamin supplements. Before taking supplements, a health care provider should be consulted. Vitamin D testing can determine if bone weakness, bone malformation, or abnormal metabolism of calcium (reflected by abnormal calcium, phosphorus or PTH tests) is occurring as a result of a deficiency or excess of vitamin D.

Since vitamin D is a fat-soluble vitamin and is absorbed from the intestine like a fat, vitamin D tests can be used to monitor individuals with diseases that interfere with fat absorption, such as cystic fibrosis and Crohn’s disease, to assure that they have adequate amounts of vitamin D. Vitamin D tests are sometimes used to determine effectiveness of treatment when vitamin D, calcium, phosphorus, and/or magnesium supplementation is prescribed.

If calcium levels are low or a patient has symptoms of vitamin D deficiency, such as bone malformation in children (rickets) and bone weakness, softness, or fracture in adults, the 25 hydroxy Vitamin D test usually is ordered to identify a possible deficiency in Vitamin D. If calcium levels are high or a patient has a disease that might produce excess amounts of Vitamin D, such as some forms of lymphoma, the 1,25 dihydroxy Vitamin D test usually is ordered. When vitamin D, calcium, phosphorus, or magnesium supplementation is necessary, Vitamin D levels are sometimes measured to monitor treatment effectiveness.

As we grow older, our bodies slowly lose the ability to mobilize vitamin D, which reduces our calcium absorption rates. This creates a higher risk of osteoporosis, particularly in post-menopausal women. A study by scientists at the University of Massachusetts found that a diet rich in calcium and vitamin D can help control some symptoms of PMS, such as tearfulness, irritability and anxiety. Some studies have shown that weight loss does occur with an increase in calcium intake, while others studies refute this. However, people with a reduced capacity to mobilize vitamin D often weigh more and have more body fat than those with full capacity. In the past 20 years multiple studies have shown a correlation between higher levels of vitamin D in the blood and leaner body mass.

Seasonal affective disorder, or SAD, is a mood disorder impacted by decreased daylight in the winter months. Vitamin D supplements are a very effective, natural remedy for SAD. Vitamin D levels are inversely related to those of melatonin, another mood-regulating hormone. Melatonin helps modulate your circadian rhythms. Darkness triggers melatonin secretion in your brain, helping to bring about relaxation at night for sleep. Insomnia, mood swings and food cravings are influenced by melatonin. Sunlight shuts melatonin production off, and triggers the release of vitamin D.

Shift workers often have less access to normal sunlight. In addition, they themselves indicate that their nutritional habits need improvement. So shift workers should make sure they and their health care provider assess which combination of sun, diet or supplements is the best to maximize their Vitamin D intake.

©2007workingnights
This material is provided for personal, non-commercial, educational and informational purposes only and does not constitute a recommendation or endorsement

Tags: biological clock, circadian rhythms, fatigue, sunlight, vitamins, Working Nights