It’s a common belief that vitamin-D deficiency is a thing of the past since many foods are fortified with the nutrient. Yet in the past few years, researchers all over the world have found that this deficiency is quite common. About one billion people worldwide don’t have high enough levels of vitamin D. This three-part article explores this issue, which is an unnecessary epidemic.
One study found that anywhere from 40% to 100% of older adults in the U.S. have vitamin-D deficiency. More than half of postmenopausal women who take drugs for osteoporosis are deficient. This goes on and on: 52% of Hispanic and African-American adolescents; 48% of young girls in Maine; 42% of women under 50 by the end of winter; 97% of Canadians during some point in winter; and 32% of healthcare workers in a Boston hospital, even though they drank a glass of milk and took a multivitamin each day, and ate salmon at least once a week.
There are many causes of vitamin-D deficiency. Here are the most common, along with their contributing factors:
1. Reduced sun exposure:
— Living at higher than the 37th parallel during wintertime
— Having dark skin
— Using sunscreen for the first moments in sun
2. Reduced dietary intake:
— Eating less vitamin D-rich foods, such as fatty fish, fish liver oil
— Following a vegetarian and no-milk diet
3. Aging:
— Your skin and kidneys don’t make as much vitamin D anymore
— You don’t drink as much milk
— You are bound to a house or nursing home
4. Health conditions:
— Obesity: not outdoors as much and the vitamin D is bound to fat
— Liver disease: vitamin not well-absorbed in gut and liver not making as much
— Kidney disease: produce less active vitamin D and some lost in urine
— Hyperthyroidism: body doesn’t make as much
5. Medications
— Laxatives, “Olestra,” “Orlistat,” cholestyramine and colestipol reduce absorption
— Anticonvulsants, cimethidine, diuretics and lithium reduce vitamin D levels