What Are the Symptoms of Low Vitamin D?

Low vitamin D may be caused by:

• Low levels of vitamin D in the diet along with inadequate sun exposure
  • Human breast milk contains low levels of vitamin D, and most infant formulas contain inadequate levels of vitamin D
  • Older adults may not consume enough vitamin D-rich foods, and when they do, absorption may be limited
• Certain conditions that result in an inability to absorb vitamin D from the intestines
  • Crohn's disease
  • Celiac disease
  • Cystic fibrosis
  • Surgery that removes or bypasses portions of the stomach or intestines such as gastric bypass
• An inability to process vitamin D due to kidney or liver disease
• Certain medications
  • Laxatives
  • Weight loss medications 
  • Cholesterol-lowering drugs 
  • Steroids
  • Anti-seizure medications    
  • Tuberculosis medication
• Other factors
  • Not going outside often, such as those who are ill or housebound
  • Living in institutions such as nursing homes
  • Wearing clothes that cover most of the skin when outdoors
  • Having dark skin, because people with dark skin may not produce sufficient vitamin D from sunlight
  • Obesity

• Low levels of vitamin D are diagnosed with a blood test called 25-hydroxyvitamin D or 25(OH)D (OH = hydroxy, D = vitamin D). 
• X-rays to check the bones may also be indicated. 

Treatment for low vitamin D includes:

• Vitamin D supplements
  • Cholecalciferol (vitamin D3) - vitamin D3 is usually recommended because it is the naturally occurring form of the vitamin and it may raise vitamin D levels more effectively
  • Ergocalciferol (vitamin D2) 
  • The recommended dose of vitamin D depends upon the nature and severity of the vitamin D deficiency
• Additional supplements
  • Calcium 
    • 1000 mg of calcium per day for premenopausal women and men 
    • 1200 mg per day for postmenopausal women

Foods that are good sources of vitamin D include:

• Oily fish
  • Trout
  • Salmon
  • Sardines
  • Herring
  • Mackerel
  • Tuna
• Meat and poultry
  • Red meat
  • Beef liver
  • Chicken breast
  • Ground beef
• Vegetables
  • Mushrooms – white and portabella
• Dairy products
  • Milk, vitamin D fortified
  • Cheddar cheese
• Other
  • Cod liver oil
  • Plant-based milks (e.g., soy, almond, oat), vitamin D fortified
  • Egg yolks
  • Ready-to-eat cereals, vitamin D fortified

Exposure to sunlight is a source for vitamin D but too much sun exposure can cause sunburns, premature skin aging, eye damage, heat exhaustion or heat stroke, or skin cancer. Exposure to the sun is not recommended as a source of vitamin D for infants and children because of the potential risks of skin cancer. Talk to your doctor about how much sun exposure you need and how to get sun exposure safely.