Falling short of the required amount could weaken immune defences, but if low levels are left untreated, discomfort may also arise.
Serena Coan, Nutritional Therapist, said: “Signs of vitamin D deficiency can be complicated as they are often just written off as “that time of the year”.
Some indicators of an early deficiency are hair loss, tiredness and not feeling refreshed after a full night of sleep, regular colds, slow wound healing and generally feeling run down, she said.
“Longer-term signs are aches and pains in muscles, joints and bones, potentially leading to bone disorders from insufficient calcium absorption.”
She said symptoms of vitamin D deficiency can take months to years to develop, depending on age, activity, and other factors.