Vitamin D deficiency and Health Consequences - Nutrition News Feb 2010.

Nutrition News Feb 2010.________________________________________
Vitamin D deficiency and Health Consequences

Vitamin D deficiency is now recognized as a world-wide problem with health consequences. The major cause of vitamin D deficiency is the lack of appreciation that sun exposure in moderation is the major source of vitamin D for most humans. Increased skin pigmentation markedly reduces vitamin D synthesis. Inadequate dietary intake, winter season, latitude, aging, medication and certain medical condition are also associated with increased risk of vitamin D deficiency.

In Australia and New Zealand , a dramatic increase in skin cancer rates resulted in the promotion of sun-safe policy to avoid exposing the skin to direct sunlight without sun protection, i.e., clothing or sunscreen. This message has resulted in a marked increase in the risk of vitamin deficiency in Australia and New Zealand... Studies suggest that upwards of 30–50% of children and adults worldwide are at risk of vitamin D deficiency.

Very few foods naturally contain vitamin D, which is found in small quantities in foods such as fatty fish, Liver, and eggs. Foods that are fortified with vitamin D are often inadequate to satisfy either a child’s or an adult’s vitamin D requirement.

Vitamin D deficiency can have musculoskeletal and nonskeletal consequences.
• It causes growth retardation and rickets in children and will precipitate and exacerbate osteopenia, osteoporosis, and fractures in adults
• It has been associated with proximal muscle weakness, increase in body sway, and an increased risk of falling
• It has been associated with increased risk of common cancers, thyroid , autoimmune diseases, hypertension, and infectious diseases
Mild vitamin D deficiency is defined as serum 25-OHD levels in the range 25–50 nmol/L
Moderate vitamin D deficiency is defined as serum 25-OHD levels of 12.5–25 nmol/L
Severe vitamin D deficiency is defined as Serum 25-OHD levels of < 12.5 nmol/L.

A circulating level of 25-hydroxyvitamin D of >75 nmol/L, or 30 ng/mL, is required to maximize vitamin D’s beneficial effects for health. In the absence of adequate sun exposure, at least 800–1000 IU vitamin D3/day may be needed to achieve this level in children and adults. To treat moderate to severe vitamin D deficiency, supplementation with 3000-5000 IU/day for 6–12 weeks is often recommended.

Source: Am J Clin Nutr 2008;87(suppl):1080S– 6S. MJA 2005; 182 (6):281-285