Vitamin D Deficiency

It is estimated that sensible sun exposure on bare skin for 5-10 minutes twice or thrice a week allows the body to produce adequate amounts of vitamin D. However, this vitamin has a half-life of only 2 weeks, meaning that vitamin D stores can be depleted. Recent studies have suggested that vitamin D deficiency affects almost 50% of adults and children worldwide. [252] Because of the extensive benefits of vitamin D for human health, the United States Department of Agriculture (USDA) recently increased the recommended daily allowance for vitamin D for adults and the American Academy of Pediatrics recommends that children get adequate vitamin D.
The following are the recommended intakes of vitamin D throughout life: [253]

• Infants 0-12 months – 400 IU (10 mcg)
• Children 1-18 years – 600 IU (15 mcg)
• Adults to age 70 – 600 IU (15 mcg)
• Adults over 70 – 800 IU (20 mcg)
• Pregnant or lactating women – 600 IU (15 mcg)

Causes of Vitamin D Deficiency
There are certain medical conditions and factors that can cause a deficiency in vitamin D. These include the following:

• Kidney and liver diseases: These medical conditions decrease the production of an enzyme needed to convert vitamin D to its useable form.
• Cystic fibrosis, Crohn’s disease, and celiac disease: These diseases prevent the intestines from absorbing adequate amounts of vitamin D.
• Gastric bypass surgery: This medical procedure involves removal of a part of the stomach and/or the intestines in order to reduce food intake and achieve significant weight loss. However, this weight-loss surgery impairs vitamin D absorption.
• Obesity: High amounts of fat hold onto the vitamin D, preventing it from being released into the bloodstream.
• Age: With advancing age, the skin’s ability to produce adequate amounts of vitamin D lessens.
• Skin color: People with dark-colored skin produce lesser amounts of vitamin D than those with fair-colored skin.
• Certain medications: Laxatives, steroids, seizure medications, weight-loss drugs, and cholesterol-lowering drugs decrease vitamin D levels in the body as a side effect.

Symptoms of Vitamin D Deficiency
In men and women with vitamin D deficiency, the symptoms are generally subtle so they may not notice them easily, even if it’s having a significant impact in their quality of life. The common signs and symptoms of vitamin D deficiency are the following:

• Anxiety
• Bone loss
• Chronic pain
• Depression
• Erectile dysfunction
• Extreme fatigue
• Getting sick or infected often
• Hair loss
• High blood pressure
• Impaired wound healing
• Inflammation and swelling
• Joint and muscle pain
• Reduced libido
• Sleeping difficulties

If you are suffering from symptoms of vitamin D deficiency, it is recommended to consult immediately with your doctor to get your vitamin D levels checked. A detailed physical examination will also help rule out any medical conditions, risk factors for vitamin D deficiency, and other factors that may affect vitamin D levels. If left untreated, severely low levels of vitamin D can lead to osteomalacia in adults, and rickets in children. Both of these diseases can lead to soft and weak bones, bone and muscle pain, and higher incidence of fractures.
Vitamin D Food Sources
Sunlight is the most cost effective way of boosting vitamin D stores. However, for people living in northern latitudes and for dark-skinned people, getting adequate amounts of vitamin D through sun exposure can be a problem. Fortunately, they can still load up on this vitamin by consuming the following foods:

• Beef liver
• Cheese
• Cod liver oil
• Egg
• Fortified skim milk
• Herring
• Raw maitake mushrooms
• Salmon
• Sardines
• Swordfish
• Tuna
• Yogurt