Vitamin D deficiency

January 23, 2024

Dr. Benyamin Mansoori

MD, FRACGP, FACAM
Advance Diploma in General Dermatology
Diploma of Cosmetic Medicine

Vitamin D deficiency is a condition where your body lacks sufficient vitamin D for optimal health.

In Australia, more than one-third of adults experience varying degrees of vitamin D deficiency.

The Australian government sets recommended daily intakes for all vitamins. For vitamin D, the guidelines suggest 5μg (micrograms) daily for individuals from infancy to 50 years, 10μg for those aged 51-70, and 15μg for those over 70 years old.

Symptoms of Vitamin D deficiency

Vitamin D, a fat-soluble vitamin, can be stored in the body, meaning short-term absence in diet or sunlight exposure might not lead to deficiency. However, prolonged lack of vitamin D can lead to conditions like osteoporosis and bone or joint pain. Older individuals with inadequate vitamin D are at a higher risk of falls and bone fractures.

Vitamin D deficiency during pregnancy can impact fetal development. Those planning a pregnancy or currently pregnant should consult their doctor about vitamin D levels.

A blood test can detect vitamin D deficiency. In Australia, health experts advise those with low vitamin D levels to take supplements, regardless of the presence or absence of deficiency symptoms.

Are You at Risk for Vitamin D Deficiency?

Vitamin D, essential for healthy body functions, comes in two primary forms. Vitamin D2 (ergocalciferol) is derived from plant sources and is found in fortified foods and some supplements. Vitamin D3 (cholecalciferol) is synthesized when sunlight hits the skin and is also present in certain animal-based foods and supplements.

While it can be challenging to obtain sufficient vitamin D from diet alone, most Australians can meet their vitamin D needs through routine outdoor activities.

The necessary sun exposure varies based on skin type, location, lifestyle, time of year, and time of day. It’s vital to use sunscreen and wear a hat when the ultraviolet (UV) index is high. Check the sunshine map for recommended sun exposure based on your location in Australia.

High-Risk Groups for Vitamin D Deficiency

Older individuals or those in care facilities like hospitals or aged-care homes
Individuals who spend most of their time indoors or have limited mobility
People with gastrointestinal diseases
Individuals on certain medications, such as epilepsy treatments
Those who cover their skin for religious or cultural reasons
Individuals with darker skin
Pregnant individuals
Postmenopausal individuals

Seasonal variations also influence vitamin D deficiency risk, with more outdoor time in warmer months and less in winter.

Impacts of Vitamin D Deficiency

Vitamin D is crucial for calcium absorption. Babies with low calcium can experience seizures, and children with severe vitamin D deficiency may develop rickets, characterized by bone and muscle pain due to soft bones.

Older adults lacking vitamin D face higher risks of bone fractures due to low calcium levels and a weaker immune system. Long-term deficiency can lead to conditions like osteoporosis or osteomalacia (soft bones in adolescents or adults, akin to rickets).

Excess Vitamin D and Its Effects

Sun-derived vitamin D doesn’t cause toxicity, but excessive UV radiation exposure significantly raises skin cancer risk. Sunscreen use does not result in vitamin D deficiency.

However, chronic high intake of vitamin D supplements can lead to vitamin D toxicity, primarily manifesting as hypercalcemia (excessive calcium in the blood), with symptoms like nausea, dehydration, and constipation.

Reference:

Healthy Bones Australia (Vitamin D and bone health), NHMRC (Nutrient Reference Values for Australia and New Zealand Vitamin D), Healthy WA (Vitamin D), NPS medicinewise (supplementation is musculoskeletal health), Cancer Council Australia (Vitamin D), Jean Hailes (Vitamin D), Royal Children’s Hospital Melbourne (Kids health information – vitamin D)