Vitamin D deficiency is very common and most people are unaware they have it. That's because the symptoms are often subtle or the symptoms are mistaken for something else. Some symptoms of deficiency are sleepiness, fatigue, moodiness, depression, hair loss, body aches and pains. Vitamin D is essential in optimizing your skin's immune system and helps destroy free radicals that can lead to premature aging. However, too much exposure to the sun can accelerate the skin aging leading to pre-mature wrinkles, suns spots and increased risk of skin cancer. Fortunately, Vitamin D deficiency is usually easy to fix by increasing your sun exposure (in moderation and being sure not to burn) and eating more vitamin D-rich foods such as fatty fish like Salmon or Tuna or fortified dairy products. Winter time is especially important to increase your Vitamin D intake due to the lack of sun exposure. Supplement your intake with 1000u of Vitamin D liquid or tablets and be sure to take it with calcium for best absorption. If you are not sure whether you are deficient a simple blood test can diagnose it. Speak with your doctor.