Obesity to lack of Vitamin D?

Genetic data from 21 studies was analysed in a report in the journal PLOS Medicine. There was a 4% drop in the vitamin D available in the body for every 10% of BMI increase.
The vitamin is stored in fatty tissue, so why is less available in people with more of it? It was suggested that the larger storage capacity in obese people (BMI > 30) may prevent vitamin D from circulating the bloodstream.

What is Vitamin D?

It helps regulate the amount of calcium and phosphate in the body. 

Sources of vitamin D include: oily fish, eggs, fortified fat spreads, fortified cereals. But the body can also synthesise it when sun exposure is adequate, and so cannot be strictly scientifically called a vitamin (as the body can produce it in sufficient amounts normally, without including it in diet).

Healthy levels are about 50 nanomoles litre. Less than 30 can cause softening and weakening of bones- leading to rickets and osteomalacia.

Obese groups are not acknowledged normally as being at risk of vitamin D deficiency, those that are include: pregnant women, age under 5, aged 65 and over, people with darker skin and people who are not exposed to much sunlight. These groups are recommended to take vitamin D supplements.