Vitamin D is produced in the skin as a result of exposure to ultraviolet (UVB) radiation from the sun. In the spring and summer months, the body is able to make more vitamin D than in the autumn and winter months because of the sun. Vitamin D is also introduced into the body through the food we eat and by supplements.

It is a fat-soluble vitamin that helps to regulate calcium and phosphates in the body. It increases the absorption of calcium and phosphates from the gastrointestinal tract, increases the amount of calcium retained in the kidneys and helps maintain calcium in the bones, all of which are important in the formation of healthy bone.

In general, the recommended daily allowance is:

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

Some sources of Vitamin D

• Liver
• Red meat
• Some fish like sardines, salmon, herring, and mackerel
• Shrimp
• egg yolk
• Cheese
• Mushroom
• Fortified orange juice
• Fortified milk
• Fortified cereal
• Fortified yogurt
• Supplements: There are two forms of vitamin D that can be bought over the counter. Vitamin D2 (ergocalciferol) is made by plants and vitamin D3 (cholecalciferol) made by animals and humans.

Some causes of Vitamin D deficiency

• Lack of sun exposure
• Use of sunscreen (It is still important to use sunscreen)
• Dark skin reduces the absorption of UVB rays from the sun which reduces vitamin D production.
• The ability to produce vitamin D decreases with age
• Winter months due to sunlight reduction

Some symptoms of Vitamin D deficiency

• Bone or muscle weakness
• Aches and pains
• Stress fractures
• Tiredness
• Osteoporosis
• Joint stiffness
• Rickets in children

Vitamin D is used in the treatment of

• Low calcium levels
• Or prevention of osteoporosis
• Or prevention or rickets a bone disease in children that causes weak bones and done deformities
• Treatment of secondary hypoparathyroidism a condition that causes abnormal blood levels of calcium and phosphorus.
• Treatment of osteomalacia which is a softening of bones

Effects of too much Vitamin D in the body:

• Too much calcium and phosphates in the blood
• Calcification of the bones
• Hardening of blood vessels and tissues of the heart, lungs, and kidneys
• Muscle and bone pain
• Diarrhea
• Nausea, vomiting
• Dry mouth
• Headaches
• Dizziness
• Loss of muscle coordination, weakness
• Problems with the rhythm of your heart

Vitamin D is also available in different forms as topical agents to be used in the treatment of psoriasis. Examples are calcipotriene (Dovonex) and calcitriol (Vectical).

It is important to have a well-balanced diet, get as much sun as you can safely of course and discuss any vitamin D supplementation with your doctor.

It is also very important to have a yearly wellness visit with your doctor because they test the levels of vitamin D in your blood. Contact your doctor if for any reason you feel unwell or if you think there’s something wrong.

Disclaimer: This is not an exhaustive list and is for information only. This is not medical advice. Please consult your doctor or pharmacist if you need personal treatment options or have any questions that affect you directly.