The role of Vitamin D in maintaining a healthy immune system
Dr. S K Wangnoo
MD, DM (Endocrinology), FRCP (London)
Indraprastha Apollo Hospitals, New Delhi
Vitamin D supplementation and autoimmune diseases
Dr. S K Wangnoo of Apollo Hospital, Delhi explains that “Even though our body needs a competent immune system to fight bodies that are foreign to it, sometimes the body develops antibodies to its own cells and this abnormality can result in many diseases which are known as auto immune disorders”. “Rheumatoid arthritis, multiple sclerosis, and Crohn’s disease are some common examples of such disorders which result in tissue damage and loss of function of the tissues or organs affected”, he further adds.
He further added that, “research has shown Vitamin D to be been linked to the incidence and severity of many autoimmune diseases such as multiple sclerosis, type 1 diabetes and irritable bowel disease. and that cholecalciferol supplementation, also known as vitamin D3, has many beneficial clinical effects in these disorders”. These benefits include the following findings:
- Vitamin D supplementation in early childhood can lower the risk of type 1 diabetes by 30%.
- The incidence of rheumatoid arthritis is lowered by Vitamin D supplement intake.
- Topical Vitamin D is being used to treat psoriasis.
- In adult patients with Crohn’s disease, Vitamin D supplementation might reduce the risk of relapses.
- Vitamin D supplementation in Systemic Lupus Erythematosus has shown decreasing disease activity, score auto-antibody levels and fatigue.
Vitamin D can be obtained from dietary sources and supplements. Currently, cholecalciferol is the most used supplementation form in clinical practice.
Recommended dietary intake for vitamin d for optimum bone health and muscle function
| Age group | Recommended dietary intake |
| Infants and children 0-1 year | 400 – 600 IU/d of vitamin-D |
| Adults aged 19-50 year | 600 IU/d of vitamin-D |
| Pregnant and lactating women | 800 -1000 IU/d of vitamin-D |
| Obese children and adults on anticonvulsant medications , glucocorticoids, antifungals and medications for AIDS | Twice or thrice times more vitamin-D for their age group. |
Treatment and Prevention strategy
The dosage varies according to the age:
| Age group | Regimen | Target 25(OH)D | Maintenance therapy |
| For infants and toddlers aged 0–1 year | 2000 IU/d of vitamin D2 or vitamin D3, or with 50,000 IU of vitamin D2 or vitamin D3 once weekly for 6 week |
Above 30 ng/ml |
400-1000 IU/d |
| For children aged 1-18 year | 2000 IU/d of vitamin D2 or vitamin D3, or with 50,000 IU of vitamin D2 once weekly for 6 week | Above 30ng/ml | 600-1000 IU/d |
| For adults | 50,000 IU of vitamin D2 or vitamin D3 once weekly for 8 week or 6000 IU of vitamin D2 or vitamin D3 daily | Above 30ng/ml | 1500-2000 IU/d |
| For obese patients, patients with mal absorption syndromes, patients on medications | two or three times higher dose ; at least 6000-10000 IU/d of vitamin D | Above 30ng/ml | 3000-6000 IU/d |
Dr. S K Wangnoo says that in his clinical practice, he uses Vitamin D as it acts as a modulator of immune function and Vitamin D supplementation actually helps to directly reduce the severity of many auto immune disease he treats, or assist the other medications he prescribes by acting in a synergistic way.
Reference:
Summary recommendations https://academic.oup.com/jcem/article-lookup/doi/10.1210/jc.2011-0385
