Vitamin D deficiency is a global public health issue. About 1 billion people worldwide are deficient, while 50% of the population has vitamin D insufficiency. The prevalence of patients with vitamin D deficiency is highest in the elderly, obese patients, nursing home residents, and hospitalized patients. It may be related to populations who have higher skin melanin content and who use extensive skin coverage, particularly in Middle East countries.
Vitamin D plays a crucial role in calcium homeostasis and bone metabolism. With prolonged and/or severe vitamin D deficiency, a drop in intestinal calcium and phosphorus absorption leads to low calcium levels in the body, in turn causing the parathyroid gland to produce more hormone (secondary hyperparathyroidism) which hastens bone mineral loss. Over time, this causes bone softening and osteoporosis in adults, and also rickets in children.
The majority of patients with vitamin D deficiency do not have any symptoms. However, even chronic, mild vitamin D deficiency can lead to low calcium levels and secondary hyperparathyroidism, which in turn contribute to the risk of falls and fractures (especially in the elderly population). Patients with prolonged and severe vitamin D deficiency may experience a range of symptoms including bone pain, joint and muscle pain, fatigue, muscle twitching (fasciculations), and generalised weakness.
In view of all the above, how do we get adequate levels of vitamin D daily?
Unprotected sun exposure is still a major source for both children and adults.

Provision of vitamin D from sunlight is as follows:
- Sensible sun exposure (between the hours of 10 am and 3 pm) produces vitamin D in the skin that may last twice as long in the blood compared with ingested vitamin D.
- Full-body sun exposure producing slight pinkness in light-skinned persons results in vitamin D production equivalent to ingesting 10,000-25,000 IU of supplement.
- As mentioned earlier, increased skin pigmentation, aging, and sunscreen use reduce the skin’s vitamin D3 production hence this is why most Malaysians are deficient.
Various foods are also important sources of vitamin. The recommended dietary intake:
• In infants and children up to 1 year old, at least 400 IU per day
• In children and adolescents 1-18 years of age, at least 600 IU per day
• In adults 19-70 years of age, at least 600 IU per day
• In adults above 70 years of age, 800 IU per day
The following foods contain the indicated amounts of vitamin D, as reported by the US Department of Agriculture’s (USDA’s) Nutrient Data Laboratory: fortified milk (8oz) 100 IU, pickled herring (100g) 680 IU, canned salmon with bones (100g) 624 IU, mackerel (100g) 360 IU, canned sardines (100g) 272 IU, codfish (100g) 44 IU, raw shiitake mushrooms (100g) 76 IU while sundried shiitake mushrooms (100g) 1600IU, and most multivitamins (1 tab) 400 IU.

If you suspect you lack vitamin D, please come in for blood tests to confirm the diagnosis. Here at DTAP we have D-Cure supplement for treating both vitamin D deficiency and insufficiency.
References:
Sizar O, Khare S, Goyal A, et al. Vitamin D Deficiency. [Updated 2022 Jul 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan.
Vin Tangpricha, MD, PhD, Vitamin D Deficiency and Related Disorders, emedicine.medscape.com, accessed 24 November 2022.