Get Started
Get Started
570-558-0290

Health & Exercise Forum

Spring is here … the days are longer and sun stronger! How's your Vitamin D?

, , , , , , , , , , , , ,
May 15, 2024

Most would agree that this spring has a little cloudy, rainy and cool in NEPA. However, warm sunny days are soon to come. While protection from the sun is very important, too much time indoors playing computer games and watching television, can lead to potential problems from lack of exposure to the sun. One must use good judgment and have balance as the potential exists for Vitamin D deficiency due to lack of sun exposure. This problem may be true for individuals who use too much protection or spend most of their day indoors due to occupation or poor health. Therefore, it will be the purpose of this column to discuss the importance of Vitamin D for health and wellness.

Vitamin D, a fat soluble vitamin, is found in food and can be made by your body after exposure to ultraviolet (UV) rays from the sun. The liver and kidney help convert it to its active form. Therefore, vitamin D assists calcium absorption, which is essential for normal development and in forming and maintaining strong bones and teeth. Without it, bones can become thin, brittle and soft. The classic Vitamin D deficiency diseases are rickets in children and osteomalacia in adults. Rickets results in skeletal deformities. Osteomalacia is the softening of bones. Therefore, it is essential for normal bone health and may diminish or prevent the onset of osteoporosis in the elderly.

The requirement for Vitamin D is dependent on age, sex, degree of sun exposure and the amount of pigmentation in the skin. Since it can be produced by the body and retained for long periods of time by the body’s tissues, the precise daily requirement has been difficult to determine. Instead, an Adequate Intake (AI) level has been established. AI is a level of intake sufficient to maintain healthy blood levels of an active form of Vitamin D.

AIs are similar for males and females but increase with age:

  • Ages 19-50: 200 International Units (IU)
  • Ages 51-69: 400 IU
  • Age 70 and older: 600 IU

Sources of Vitamin D:

  • Food Sources
    • Fortified foods are a major dietary source:
      • One cup of Vitamin D fortified milk: 98 IU
      • Dairy products (e.g. cheese, yogurt, ice cream) are generally not fortified
      • Orange juice, cereals, pastries, breads, crackers, cereal grain bars may be fortified; read the nutrition label for more information.
    • Only a few foods naturally contain significant amounts:
      • Salmon, cooked, 3 ½ oz: 360 IU
      • Mackerel, cooked, 3 ½ oz: 345 IU
      • Sardines, canned in oil, drained, 3 ½ oz: 270 IU
      • Liver, beef, cooked, 3 ½ oz: 30 IU
      • Egg yolk, one: 25 IU
  • Exposure to sunlight:
    • Regular ultraviolet exposure stimulates the skin to produce Vitamin D.
    • Exposure to ultraviolet light or ambient sunlight
    • Exposing the face and hands for 20 minutes, 3 times a week can be sufficient
    • Exposing the hands, legs and arms for 5 to 10 minutes, 2 to 3 times a week, is more than adequate to satisfy requirements.

Vitamin D Deficiency:

Vitamin D deficiency can occur when dietary intake is inadequate, when there is limited sunlight exposure, when the kidney cannot convert Vitamin D to its active form or when Vitamin D is inadequately absorbed from the gastrointestinal tract. Season, geographic location, time of day, cloud cover, air pollution, sunscreens, living indoors and living in cities where tall buildings block adequate sunlight from reaching the ground affect UV ray exposure. Therefore, individuals with limited sun exposure are at risk of this deficiency. Homebound individuals, people living in northern latitudes (e.g. New England, Alaska), individuals who cover their bodies for religious reasons and people whose occupations prevent exposure to sunlight may need to supplement in other forms.

Sunscreens with a sun protection factor of 8 or greater will block UV rays that produce Vitamin D. Older adults have a higher risk for this deficiency because the skin’s ability to convert Vitamin D to its active form decreases with age and the kidneys, which help convert Vitamin D to its active form, do not work as well when people age. Individuals with pancreatic enzyme deficiency, Chron’s disease, cystic fibrosis, sprue, liver disease, surgical removal of part or all of the stomach or small bowel disease may need extra intake because Vitamin D is a fat soluble and they have reduced ability to absorb dietary fat. Supplements are often recommended for exclusively breast-fed infants because human milk may not contain adequate Vitamin D. Consult with your pediatrician on this issue.

SOURCES: The National Institutes of Health; CDC

EVERY MONDAY – Read Dr. Paul J. Mackarey “Health & Exercise Forum!” via Blog

EVERY SUNDAY in "The Sunday Times" - Read Dr. Paul J. Mackarey “Health & Exercise Forum!” in hard copy

This article is not intended as a substitute for medical treatment. If you have questions related to your medical condition, please contact your family physician. For further inquires related to this topic email: drpmackarey@msn.com

Paul J. Mackarey PT, DHSc, OCS is a Doctor in Health Sciences specializing in orthopaedic and sports physical therapy in Scranton and Clarks Summit. Dr. Mackarey is in private practice and is an associate professor of clinical medicine at Geisinger Commonwealth School of Medicine. For all of Dr. Mackarey's articles, visit our exercise forum!