Lenten re-run # 5: Sunshine and fish oil

Sunshine and fish oil

Many adults, especially women, are in a situation of having low or borderline levels of vitamin D, the “sunshine vitamin.”  Vitamin D is a fat-soluble vitamin that is naturally present in only a very few foods; it is, however, produced by body processes when ultraviolet (UV) rays from sunlight strike the skin and trigger vitamin D synthesis.

Vitamin D promotes calcium absorption, which helps the body to utilize phosphorous; these enable normal “mineralization” of bone by assisting bone growth and bone remodeling. Without sufficient vitamin D, bones can become thin, brittle, or misshapen. Having enough vitamin D can prevent rickets in children and, along with calcium, protect adults from osteoporosis. Vitamin D has other important roles in the body: it affects cell growth, neuromuscular and immune function, and reduction of inflammation. Many different types of cells have vitamin D receptors. 

Most people meet at least some of their vitamin D needs through exposure to sunlight.  Complete cloud cover and shade reduce UV energy significantly, and persons with darker skin tones do not as readily absorb UV rays. Sunscreens with a sun protection factor (SPF) of 8 or more appear to block vitamin D-producing UV rays, but because people do not usually apply enough and do not reapply it as they should, it is felt that some UV benefit is obtained even when wearing sunscreen.  Approximately 5–30 minutes of sun exposure between 10 AM and 3 PM at least twice a week to the face, arms, legs, or back without sunscreen usually leads to sufficient vitamin D synthesis; as UV rays do not pass through glass windows, this must be direct exposure outside. It is well known, however, that it is prudent to limit exposure of unprotected skin to sunlight, as UV radiation is known to be responsible for skin cancers and metastatic melanoma.

The overall daily requirement of vitamin D from a combination of food and sunlight is 600 IU (international units) for persons one year of age and older. In the United States, all milk products, infant formulas, and many cereals are fortified with vitamin D.  Other edible sources include the flesh of fatty fish (such as salmon, tuna, and mackerel) and fish liver oils – our grandparents knew the value of giving their kids cod liver oil every day! Small amounts of vitamin D are found in beef liver, cheese, mushrooms, and egg yolks; but because exposure to sun and consumption of  D-rich foods are not likely to provide enough vitamin D, supplementation is highly recommended. Check the label on your multivitamin to be sure that you are getting the recommended daily amount!

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Donna Swope

“…….and his bones are strong and healthy.”  Job 21, v. 24