Vitamin D deficiency is a common health problem all over the world, at a time when more links between this important vitamin and many chronic diseases are constantly being identified and studied, but making up for the deficiency is not always an easy issue that can be solved by taking supplements or spending some time under the sunlight, according to a specialist doctor from the global health care system “Cleveland Clinic.”
Vitamin D benefits
“The benefits of vitamin D for the human body have only recently been recognized, although the harmful effect of insufficient exposure to sunlight in childhood has been known for centuries,” said Dr. Susan Williams, a physician in the Endocrinology and Metabolism Institute at the Cleveland Clinic.
Studies have increasingly linked vitamin D deficiency with the development of various chronic diseases, while other studies have proven a positive link between good levels of this vitamin and the optimal functions of the immune and nervous systems.
Dr. Williams noted that foods rich in vitamin D provide only a small percentage of the recommended daily need for this vitamin, with the rest coming from the sun or supplements.
Limited exposure to the sun, whether as a result of bad weather or the prevention of skin cancer, is a common cause of vitamin D deficiency, but other causes include dark skin color, advanced age, obesity, gastric bypass surgery, and some digestive diseases that lead to malabsorption, and vitamin D deficiency can occur in infants as a result of limiting their meals to breastfeeding and keeping them away from other sources of the vitamin.
Vitamin D supplements
The level of vitamin D in the body can be measured by a blood test, and there are two factors to consider if supplementation is necessary.
Dr. Williams explained that there are two types of vitamin D supplements; Vitamin D2 and Vitamin D3. While both types raise vitamin D levels, recent studies have indicated that vitamin D3 has a stronger effect over time. The way you take the supplement is also important, as studies have indicated that supplements are most effective when taken with a meal that contains at least 15 grams of fat, and taking vitamins with the largest daily meal will enhance absorption.
The metabolic specialist stressed the need to adhere to the doses prescribed by the doctor of supplements, otherwise, patients are at risk of vitamin D poisoning, noting that some patients may not respond to vitamin D supplements because of problems absorbing it, including people who have had bariatric surgery related to absorption, and those who suffer from Crohn’s disease, celiac disease, cystic fibrosis, steatorrhea, short bowel disease, enteritis, and acute cholestasis.
Malabsorption can be confirmed through blood tests, by comparing the levels of vitamin D in a blood sample taken immediately before taking an oral dose of vitamin D, and the sample taken 12 to 24 hours after the dose.
If malabsorption is confirmed, phototherapy, which includes accurate skin type identification and carefully considered exposure to ultraviolet (UV) B rays, can be used to increase vitamin levels.
Warning
However, Dr. Williams cautions patients against trying to increase their vitamin D levels by using a tanning bed or spending hours in the sunlight, describing these methods as “often ineffective and risking skin damage and skin cancer.”
She added, “To synthesize vitamin D, we need ultraviolet B rays, but the percentage of this type in the ultraviolet rays found in sunlight does not exceed five percent, while tanning beds mainly or exclusively use ultraviolet A rays, and the dose of ultraviolet A radiation in these beds can reach 12 times that of sunlight, and both types of radiation play a role in the development of skin cancers, but it is believed that ultraviolet A rays damage the skin and increase the risk of cancer by causing damage to the DNA, due to oxidative stress, while the damage of type B rays is more direct in the phototrophic products implicated in skin carcinogenesis.
Dr. Williams concluded that skin type and a person’s age affect the response to exposure to ultraviolet rays, but in general, exposing 5 percent of the body’s surface twice a week for 20 minutes in warm months may be equal to getting 430 international units of vitamin D per day, stressing the need to adhere to the maximum time, which is 20 minutes, due to the risks associated with increased exposure to sunlight.
