VITAMIN D & HEALTH

How much Vitamin D do I need to stay healthy?

Vitamin D levels in our body are measured by performing a blood test for 25-hydroxyvitamin D [25(OH)D], the major circulating form of Vitamin D in our blood. Individuals with 25(OH)D levels below 20 ng/mL (50 nmol/L) are classified as Vitamin D deficient.^1,2

25(OH)D levels above 20 ng/mL are generally adequate for good bone and muscle health.^1,3 However, many experts and international guidelines suggest that a level of at least 30 ng/mL (75 nmol/L) is optimal for overall health, especially in the elderly or individuals at increased risk of Vitamin D deficiency.^2,4

The optimal amount of Vitamin D needed daily to maintain healthy levels in the bloodstream changes with age.^1,2 The table below summarises the recommended Vitamin D intake per day at different life stages.

Table 1: Recommended dietary intake for vitamin D^1,2

Age

Minimum amount
required per day*

Equivalent minimum
monthly dose for reference

Infants (0–12 months)

400 IU (10 mcg)

12,000 IU (300 mcg)

Children and adults (1–70 years)

600 IU (15 mcg)

18,000 IU (450 mcg)

Elderly (>70 years)

800 IU (20 mcg)

24,000 IU (600 mcg)

Minimum amount
required per day*

400 IU (10 mcg)

Equivalent minimum
monthly dose for reference

12,000 IU (300 mcg)

Age

Children and adults (1–70 years)

Minimum amount
required per day*

600 IU (15 mcg)

Equivalent minimum
monthly dose for reference

18,000 IU (450 mcg)

Age

Elderly (>70 years)

Minimum amount
required per day*

800 IU (20 mcg)

Equivalent minimum
monthly dose for reference

24,000 IU (600 mcg)

*Assuming limited Vitamin D production by skin due to minimal sun exposure.

Although these are general guidelines for Vitamin D intake by otherwise healthy people, there is no one-size-fits-all dosage. For example, patients who are Vitamin D deficient may require much higher treatment and maintenance doses.²Additionally, people at risk of developing Vitamin D deficiency, such as those who habitually wear sunscreen, have a dark complexion, or get little sunlight exposure, may need higher maintenance doses.¹

Vitamin D needs depend on each person’s individual risk profile, which should be assessed by a healthcare provider.

References
1) National Institutes of Health. Vitamin D Fact Sheet for Health Professionals. Available at: https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/. Accessed 30 June 2021.
2) Holick MF, et al. J Clin Endocrinol Metab 2011;96:1911-1930.
3) Nair R, Maseeh A. J Pharmacol Pharmacother 2012;3:118-126.
4) Gani LU, How CH. Singapore Med J 2015;56:433-437.